Update docs/clion.md

- Replaced 'Building, Running, and Debugging' section
  - Previously, this section was incomplete and only described how to
build chromium.
  - Added instructions to run and visually debug as well.
  - Updated build instructions to support debugging.
- Simplified recommended CMakeLists.txt file
- Simplified instructions for creating a desktop entry
- Increased recommended VM option Xmx from 5g to 10g
- Marked optional steps as optional
- Punctuation fixes
- Added link to clion.md to docs/README.md

Change-Id: Id0514b1498517e0c10fafb1a9639aeda44717921
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1976280
Commit-Queue: manuk hovanesian <[email protected]>
Reviewed-by: Tommy Li <[email protected]>
Cr-Commit-Position: refs/heads/master@{#726546}
diff --git a/docs/README.md b/docs/README.md
index bc8ebd0..764812c3 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -68,14 +68,15 @@
 
 ### Integrated Development Environment (IDE) Set Up Guides
 *   [Android Studio](android_studio.md) - Android Studio for Android builds
+*   [Atom](atom.md) - Atom multi-platform code editor
+*   [CLion](clion.md) - CLion IDE, supports GUI debugging.
 *   [Eclipse for Android](eclipse.md) - Eclipse for Android
 *   [Eclipse for Linux](linux_eclipse_dev.md) - Eclipse for other platforms
     (This guide was written for Linux, but is probably usable on Windows/MacOS
     as well)
-*   [Qt Creator](qtcreator.md) - Using Qt Creator as an IDE or GUI debugger
-*   [Setting up Visual Studio Code](vscode.md) - Visual Studio Code
 *   [EMACS Notes](emacs.md) - EMACS commands/styles/tool integrations
-*   [Atom](atom.md) - Atom multi-platform code editor
+*   [Qt Creator](qtcreator.md) - Using Qt Creator as an IDE or GUI debugger
+*   [Visual Studio Code](vscode.md) - Visual Studio Code
 
 ### Git
 *   [Git Cookbook](git_cookbook.md) - A collection of git recipes for common