Updates to the 'CLion Integration' section in ClangFormat docs

[MarinaKalashina]

Summary

This commit updates the 'CLion Integration' section in ClangFormat docs.
Key changes:

• clang-format is enabled automatically when there is a config file;
• formatting now works for indentations;
• if clang-format is enabled without a config file, CLion suggests creating it based on the IDE settings or uses the LLVM style by default.

[ilya-biryukov]

@sammccall, @klimek, @gribozavr2, @MyDeveloperDay who would be the best reviewer for this?
Could do the reviews myself for small CLion-related documentation changes if everyone is ok with this. Does that LG?

clang/docs/ClangFormat.rst

178–179

NIT: lines are now longer than before, could you wrap the text in accordance with the code style?

179–186

NIT: we should probably use :program:'clang-format' (with backticks instead of ', couldn't figure out how to escape them in markdown), for consistency with the rest of the document.

[MarinaKalashina]

linewidth corrected; "Clang-Format" changed to ":program:clang-format"

[klimek]

In D80721#2079534, @ilya-biryukov wrote:

@sammccall, @klimek, @gribozavr2, @MyDeveloperDay who would be the best reviewer for this?
Could do the reviews myself for small CLion-related documentation changes if everyone is ok with this. Does that LG?

I think that's makes lots of sense, as I think none of us are in a very good position to review those (I'd personally just LG them :)
Thanks!

[ilya-biryukov]

LGTM

[ilya-biryukov]

Added a few minor changes before committing:

• surround names of .clang-format files with double backticks
• ensure no lines are longer than 80 characters

clang/docs/ClangFormat.rst

 :program:`clang-format` will format the selection. Note that you can rename the
 menu item by renaming the script, and can assign the menu item a keyboard
 shortcut in the BBEdit preferences, under Menus & Shortcuts.
 
 
 CLion Integration
 =================
 
 :program:`clang-format` is integrated into `CLion <https://www.jetbrains
-.com/clion/>`_ as an alternative code formatter. It is disabled by default and
-can be turned on in Settings/Preferences | Editor | Code Style.
-
-If :program:`clang-format` support is enabled, CLion detects config files when
-opening a project and suggests overriding the current IDE settings. Code style
-rules from the ``.clang-format`` files are then applied automatically to all
-editor actions, including auto-completion, code generation, and refactorings.
+.com/clion/>`_ as an alternative code formatter. CLion turns it on
+automatically when there is a ``.clang-format`` file under the project root.
+Code style rules are applied as you type, including indentation,
+auto-completion, code generation, and refactorings.
+
+:program:`clang-format` can also be enabled without a ``.clang-format`` file.
+In this case, CLion prompts you to create one based on the current IDE settings
+or the default LLVM style.
 
 
 Visual Studio Integration
 =========================
 
 Download the latest Visual Studio extension from the `alpha build site
 <https://llvm.org/builds/>`_. The default key-binding is Ctrl-R,Ctrl-F.