[include-fixer] Mention more details in the document.

[Eugene.Zelenko]

Could you please mention include-fixer in docs/ReleaseNotes.rst? This is definitely major new feature in upcoming release.

[bkramer]

Sorry, this patch somehow got buried in my mail.

docs/include-fixer.rst

69

Maybe also describe the g:clang_include_fixer_path that you can put into .vimrc?

[hokein]

Address review comments.

[hokein]

In D20467#435685, @Eugene.Zelenko wrote:

Could you please mention include-fixer in docs/ReleaseNotes.rst? This is definitely major new feature in upcoming release.

Done.

[bkramer]

docs/ReleaseNotes.rst

47 ↗

(On Diff #59721)

a tool that provides

docs/include-fixer.rst

70

add the path to clang-include-fixer to the PATH environment variable

71

in vimrc

[hokein]

Add comments.

[bkramer]

Two more nits, looks good otherwise :)

docs/include-fixer.rst

73

typo custonmize, headers being shown

[hokein]

Fix typo.

docs/include-fixer.rst

 The include fixer contains :program:`find-all-symbols`, a tool to create a
 symbol database in YAML format from a compilation database by parsing all
 source files listed in it. The following list of commands shows how to set up a
 database for LLVM, any project built by CMake should follow similar steps.
 
 .. code-block:: console
 
   $ cd path/to/llvm-build
+  $ ninja find-all-symbols // build find-all-symbols tool.
+  $ ninja clang-include-fixer // build clang-include-fixer tool.
   $ ls compile_commands.json # Make sure compile_commands.json exists.
     compile_commands.json
   $ path/to/llvm/source/tools/clang/tools/extra/include-fixer/find-all-symbols/tool/run-find-all-symbols.py
     ... wait as clang indexes the code base ...
   $ ln -s $PWD/find_all_symbols_db.yaml path/to/llvm/source/ # Link database into the source tree.
   $ ln -s $PWD/compile_commands.json path/to/llvm/source/ # Also link compilation database if it's not there already.
   $ cd path/to/llvm/source
-  $ clang-include-fixer -db=yaml path/to/file/with/missing/include.cpp
+  $ /path/to/clang-include-fixer -db=yaml path/to/file/with/missing/include.cpp
     Added #include "foo.h"
 
 Integrate with Vim
 -------------------
 To run `clang-include-fixer` on a potentially unsaved buffer in Vim. Add the
 following key binding to your ``.vimrc``:
 
 .. code-block:: console
 
   map ,cf :pyf path/to/llvm/source/tools/clang/tools/extra/include-fixer/tool/clang-include-fixer.py<cr>
 
 This enables `clang-include-fixer` for NORMAL and VISUAL mode. Change ``,cf`` to
 another binding if you need clang-include-fixer on a different key.
 
+Make sure the path of :program:`clang-include-fixer` is in the environment PATH
+variable.
+
 See ``clang-include-fixer.py`` for more details.
 
 How it Works
 ============
 
 To get the most information out of clang at parse time,
 :program:`clang-include-fixer` runs in tandem with the parse and receives
 callbacks from Clang's semantic analysis. In particular it reuses the existing
 support for typo corrections. Whenever Clang tries to correct a potential typo
 it emits a callback to the include fixer which then looks for a corresponding
 file. At this point rich lookup information is still available, which is not