UI Guidelines (#1308)

* Add UI Guidelines to  SDK docs

* Add UI Guidelines to  SDK docs

* Fixing build errors

* optimize PNGs

* add UI guidelines landing page placeholder

* IJ SDK Docs <-> UI guidelines crosslinks updated

* split_button.md: remove reference to removed setting

* use <ui-path>

* use MD instead of <note>

* use %gh-ic% links

* drop_down.md: fix <control>

* code samples: fix most obvious issues

* remove obsolete `_defaults.md`

* ijs.tree: UI cleanup

* Delete "under construction" pages

* Fix headers

* Add link-summary

* Remove invalid links

* Delete unused files

* Remove ''@2x' from image file names

* Use Markdown syntax for some images and tables

* Rename non-unique files to unique

* Remove alpha in images where content is unreadable

* align quotation marks

* Controls: cleanup/fixes, add code links, edit

* tooltip.md: fix HTML

* misc fixes

* typography.md: fix table contents

* typography.md: fix table header

* UI guidelines landing page + TOC fixes

* remove unused icons_list.md

* Normalize image paths

* validation_errors.md: Fix broken tab

* "correct"/"incorrect" labels styling

* Resize images to 50%

* button.topic: fixes

* grammar, spelling, minor edits

* remove '&nbsp;'

* fix 99px

* cleanup

* UI_kit.md: minor

* Fix "MRK058: Large image in paragraph rendered as a block element by default."

* button.topic: Add img[alt]

* mnemonics.md: Update "Contact Us" link to the IJSDK YouTrack

* split_button.md: Use ui-path

* UI landing: add feedback snippet

* Improve code snippets formatting and naming

* Fix code samples

* Fix code samples

* Add Kotlin variants for code samples

* Add icons_list.md

* crosslinks

* Change external link to https://intellij-icons.jetbrains.design/

* icons list -> https://intellij-icons.jetbrains.design

* Hide info about reducing split button to simple action button (now it is available through the registry only)

* reformat

* icons_style.md: Images in new line

---------

Co-authored-by: marianna.kononenko <marianna.kononenko@jetbrains.com>
Co-authored-by: Yann Cébron <yann.cebron@jetbrains.com>

ijs.tree

@@ -362,7 +362,8 @@
     <toc-element topic="build_number_ranges.md"/>
     <toc-element topic="intellij_artifacts.md"/>
     <toc-element toc-title="Extension Points and Listeners">
-      <toc-element toc-title="IntelliJ Platform" topic="intellij_platform_extension_point_list.md" accepts-web-file-names="extension-point-list.html"/>
+      <toc-element toc-title="IntelliJ Platform" topic="intellij_platform_extension_point_list.md"
+                   accepts-web-file-names="extension-point-list.html"/>
       <toc-element toc-title="IntelliJ Community Plugins" topic="intellij_community_plugins_extension_point_list.md"/>
       <toc-element toc-title="Android Plugin" topic="android_plugin_extension_point_list.md"/>
       <toc-element toc-title="AppCode" topic="appcode_extension_point_list.md"/>
@@ -440,4 +441,100 @@
       </toc-element>
     </toc-element>
   </toc-element>
+  <toc-element topic="ui_guidelines_welcome.md">
+    <toc-element toc-title="Controls">
+      <toc-element topic="button.topic">
+        <toc-element topic="built_in_button.md"/>
+        <toc-element topic="split_button.md"/>
+      </toc-element>
+      <toc-element topic="checkbox.md"/>
+      <toc-element topic="combo_box.md"/>
+      <toc-element topic="context_help.md">
+        <toc-element topic="inline_help_text.md"/>
+        <toc-element topic="tooltip.md"/>
+        <toc-element topic="empty_state.md"/>
+      </toc-element>
+      <toc-element topic="description_text.md"/>
+      <toc-element topic="drop_down.md"/>
+      <toc-element topic="got_it_tooltip.md"/>
+      <toc-element topic="group_header.md"/>
+      <toc-element topic="input_field.md"/>
+      <toc-element topic="link.md"/>
+      <toc-element toc-title="List"/> <!--TODO-->
+      <toc-element toc-title="Menu">
+        <toc-element toc-title="Context Menu"/> <!--TODO-->
+        <toc-element toc-title="Main Menu"/> <!--TODO-->
+        <toc-element toc-title="Menu List"/> <!--TODO-->
+      </toc-element>
+      <toc-element topic="notification_types.md">
+        <toc-element toc-title="Alert"/> <!--TODO-->
+        <toc-element topic="balloon.md"/>
+        <toc-element topic="banner.md"/>
+        <toc-element toc-title="Tool Window Balloon"/> <!--TODO-->
+      </toc-element>
+      <toc-element topic="progress_indicators.md">
+        <toc-element topic="loader.md"/>
+        <toc-element topic="progress_bar.md"/>
+        <toc-element topic="progress_text.md"/>
+      </toc-element>
+      <toc-element topic="radio_button.md"/>
+      <toc-element topic="scrollbar.md"/>
+      <toc-element topic="search_field.md"/>
+      <toc-element toc-title="Slider"/> <!--TODO-->
+      <toc-element topic="table.md"/>
+      <toc-element topic="tabs.md"/>
+      <toc-element topic="text_area.md"/>
+      <toc-element topic="toggle_button.md"/>
+      <toc-element topic="toolbar.md">
+        <toc-element topic="icon_button.md"/>
+        <toc-element topic="split_icon_button.md"/>
+        <toc-element topic="toolbar_drop_down.md"/>
+      </toc-element>
+      <toc-element toc-title="Tree"/> <!--TODO-->
+    </toc-element>
+    <toc-element toc-title="Components">
+      <toc-element toc-title="Dialog Window"/> <!--TODO-->
+      <toc-element toc-title="Popup"/> <!--TODO-->
+      <toc-element toc-title="Status Bar"/> <!--TODO-->
+      <toc-element topic="tool_window.md"/>
+    </toc-element>
+    <toc-element toc-title="Text">
+      <toc-element topic="capitalization.md"/>
+      <toc-element topic="inspections.md"/>
+      <toc-element topic="punctuation.md"/>
+      <toc-element toc-title="Notification and Error Texts"/> <!--TODO-->
+      <toc-element toc-title="Terminology"/> <!--TODO-->
+      <toc-element topic="writing_short.md"/>
+    </toc-element>
+    <toc-element toc-title="Principles">
+      <toc-element toc-title="Accessibility"/> <!--TODO-->
+      <toc-element toc-title="Dangerous Actions"/> <!--TODO-->
+      <toc-element topic="data_formats.md"/>
+      <toc-element toc-title="Default Values"/> <!--TODO-->
+      <toc-element toc-title="Discoverability"/> <!--TODO-->
+      <toc-element topic="icons_style.md"/>
+      <!--      <toc-element topic="icons.md"/>-->
+      <toc-element topic="layout.md">
+        <toc-element topic="groups_of_controls.md"/>
+        <toc-element toc-title="Master-detail Layout"/> <!--TODO-->
+        <toc-element toc-title="Sizes and Insets"/> <!--TODO-->
+      </toc-element>
+      <toc-element topic="mnemonics.md"/>
+      <toc-element topic="platform_theme_colors.md"/>
+      <toc-element toc-title="Search"> <!--TODO-->
+        <toc-element toc-title="Search Results"/> <!--TODO-->
+        <toc-element toc-title="Speed Search"/> <!--TODO-->
+      </toc-element>
+      <toc-element toc-title="Sharing Settings"/> <!--TODO-->
+      <toc-element topic="typography.md"/>
+      <toc-element toc-title="UI Feedback"/> <!--TODO-->
+      <toc-element topic="validation_errors.md"/>
+    </toc-element>
+    <toc-element toc-title="Resources">
+      <toc-element href="https://intellij-icons.jetbrains.design" toc-title="Icons List"/>
+      <toc-element topic="icons_list.md" hidden="true"/>
+      <toc-element topic="how_to_write_guidelines.md"/>
+      <toc-element topic="UI_kit.md"/>
+    </toc-element>
+  </toc-element>
 </instance-profile>

images/ui/arrow-down.svg

@@ -0,0 +1,10 @@
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+    <!-- Generator: Sketch 49.1 (51147) - http://www.bohemiancoding.com/sketch -->
+    <title>Shape Copy</title>
+    <desc>Created with Sketch.</desc>
+    <defs></defs>
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+    </g>
+</svg>

images/ui/arrow-right.svg

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="7px" height="10px" viewBox="0 0 7 10" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+    <!-- Generator: Sketch 49.1 (51147) - http://www.bohemiancoding.com/sketch -->
+    <title>Shape</title>
+    <desc>Created with Sketch.</desc>
+    <defs></defs>
+    <g id="Page-1" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd">
+        <path d="M-1.001,3.502 C-1.001,3.422 -0.971,3.352 -0.911,3.292 L-0.461,2.842 C-0.401,2.782 -0.331,2.752 -0.251,2.752 C-0.171,2.752 -0.105,2.782 -0.044,2.842 L3.499,6.386 L7.043,2.842 C7.103,2.782 7.173,2.752 7.25,2.752 C7.327,2.752 7.398,2.782 7.46,2.842 L7.91,3.292 C7.97,3.352 8,3.422 8,3.502 C8,3.582 7.97,3.648 7.91,3.708 L3.707,7.91 C3.647,7.97 3.577,8 3.499,8 C3.421,8 3.352,7.97 3.291,7.91 L-0.911,3.708 C-0.971,3.648 -1.001,3.578 -1.001,3.502 Z" id="Shape" fill="#2B2B2B" fill-rule="nonzero" transform="translate(3.499500, 5.376000) rotate(270.000000) translate(-3.499500, -5.376000) "></path>
+    </g>
+</svg>