[include-fixer] Add customized editor settings documents.

[bkramer]

lg

clang-tools-extra/trunk/docs/include-fixer.rst

 Make sure vim can find :program:`clang-include-fixer`:
 
 - Add the path to :program:`clang-include-fixer` to the PATH environment variable.
 - Or set ``g:clang_include_fixer_path`` in vimrc: ``let g:clang_include_fixer_path=path/to/clang-include-fixer``
 
 You can customize the number of headers being shown by setting
 ``let g:clang_include_fixer_maximum_suggested_headers=5``
 
+Customized settings in `.vimrc`:
+
+- ``let g:clang_include_fixer_path = "clang-include-fixer"``
+
+  Set clang-include-fixer binary file path.
+
+- ``let g:clang_include_fixer_maximum_suggested_headers = 3``
+
+  Set the maximum number of ``#includes`` to show. Default is 3.
+
+- ``let g:clang_include_fixer_increment_num = 5``
+
+  Set the increment number of #includes to show every time when pressing ``m``.
+  Default is 5.
+
+- ``let g:clang_include_fixer_jump_to_include = 0``
+
+  Set to 1 if you want to jump to the new inserted ``#include`` line. Default is
+  0.
+
+- ``let g:clang_include_fixer_query_mode = 0``
+
+  Set to 1 if you want to insert ``#include`` for the symbol under the cursor.
+  Default is 0. Compared to normal mode, this mode won't parse the source file
+  and only search the sysmbol from database, which is faster than normal mode.
+
 See ``clang-include-fixer.py`` for more details.
 
 Integrate with Emacs
 --------------------
 To run `clang-include-fixer` on a potentially unsaved buffer in Emacs.
-Ensure that Emacs finds ``clang-include-fixer.el`` by adding the directory containing the file to the ``load-path``
-and requiring the `clang-include-fixer` in your ```.emacs``:
+Ensure that Emacs finds ``clang-include-fixer.el`` by adding the directory
+containing the file to the ``load-path`` and requiring the `clang-include-fixer`
+in your ``.emacs``:
 
 .. code-block:: console
 
  (add-to-list 'load-path "path/to/llvm/source/tools/clang/tools/extra/include-fixer/tool/"
  (require 'clang-include-fixer)
 
 Within Emacs the tool can be invoked with the command ``M-x clang-include-fixer``.
 
 Make sure Emacs can find :program:`clang-include-fixer`:
 
 - Add the path to :program:`clang-include-fixer` to the PATH environment variable.
 
+Customized settings in `.emacs`:
+
+- ``(custom-set-variables '(clang-include-fixer-executable "/path/to/include-fixer"))``
+
+  Set clang-include-fixer binary file path.
+
+- ``(custom-set-variables '(clang-include-fixer-query-mode t))``
+
+  Set to `t` if you want to insert ``#include`` for the symbol under the cursor.
+  Default is `nil`. Compared to normal mode, this mode won't parse the source
+  file and only search the sysmbol from database, which is faster than normal
+  mode.
+
 See ``clang-include-fixer.el`` 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