[clang] [clang-format][NFC] Improve KeepFormFeed option decription (PR #176654)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 51860 tests passed
* 908 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Clang
<details>
<summary>Clang.Format/docs_updated.test</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
"C:\Python312\python.exe" C:\_work\llvm-project\llvm-project\clang\test\Format/../../docs/tools/dump_format_style.py -o C:\_work\llvm-project\llvm-project\build\tools\clang\test\Format\Output\docs_updated.test.tmp.style
# executed command: 'C:\Python312\python.exe' 'C:\_work\llvm-project\llvm-project\clang\test\Format/../../docs/tools/dump_format_style.py' -o 'C:\_work\llvm-project\llvm-project\build\tools\clang\test\Format\Output\docs_updated.test.tmp.style'
# note: command had no output on stdout or stderr
# RUN: at line 2
diff --strip-trailing-cr C:\_work\llvm-project\llvm-project\build\tools\clang\test\Format\Output\docs_updated.test.tmp.style    C:\_work\llvm-project\llvm-project\clang\test\Format/../../docs/ClangFormatStyleOptions.rst
# executed command: diff --strip-trailing-cr 'C:\_work\llvm-project\llvm-project\build\tools\clang\test\Format\Output\docs_updated.test.tmp.style' 'C:\_work\llvm-project\llvm-project\clang\test\Format/../../docs/ClangFormatStyleOptions.rst'
# .---command stdout------------
# | *** C:\_work\llvm-project\llvm-project\build\tools\clang\test\Format\Output\docs_updated.test.tmp.style
# | --- C:\_work\llvm-project\llvm-project\clang\test\Format/../../docs/ClangFormatStyleOptions.rst
# | ***************
# | *** 5014,5023 ****
# |   **KeepFormFeed** (``Boolean``) :versionbadge:`clang-format 20` :ref:`¶ <KeepFormFeed>`
# |     Keep the form feed character (``\f``) if it's immediately preceded and
# |     followed by a newline. Multiple form feeds and newlines within a
# | !   whitespace range are replaced with a single newline and form feed followed
# | !   by the remaining newlines. (See
# | !   https://www.gnu.org/prep/standards/html_node/Formatting.html#:~:text=formfeed
# | !   for more information.)
# |   
# |   .. _LambdaBodyIndentation:
# |   
# | --- 5014,5023 ----
# |   **KeepFormFeed** (``Boolean``) :versionbadge:`clang-format 20` :ref:`¶ <KeepFormFeed>`
# |     Keep the form feed character (``\f``) if it's immediately preceded and
# |     followed by a newline. Multiple form feeds and newlines within a
# | !   whitespace range are replaced with a single newline and form feed
# | !   followed by the remaining newlines. See
# | !   `GNU formfeed coding standard <https://www.gnu.org/prep/standards/html_node/Formatting.html#:~:text=formfeed>`_
# | !   for more information.
# |   
# |   .. _LambdaBodyIndentation:
# |   
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/176654