[clang-tools-extra] [clang-tidy][docs] Rename short check docs to Markdown (PR #210466)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-ubuntu-fast` running on `sie-linux-worker` while building `clang-tools-extra` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/144/builds/59975

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang Tools :: clang-tidy/infrastructure/update-checks-list.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/usr/bin/python3.10 /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang-tools-extra/test/clang-tidy/infrastructure/../../../clang-tidy/tool/check_update_docs.py -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/clang/tools/extra/test/clang-tidy/infrastructure/Output/update-checks-list.test.tmp.clang-tidy-checks-list.rst
# executed command: /usr/bin/python3.10 /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang-tools-extra/test/clang-tidy/infrastructure/../../../clang-tidy/tool/check_update_docs.py -o /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/clang/tools/extra/test/clang-tidy/infrastructure/Output/update-checks-list.test.tmp.clang-tidy-checks-list.rst
# .---command stderr------------
# | 
# | 'clang-tools-extra/docs/clang-tidy/checks/list.rst' is out of date.
# | Fix it by running 'clang-tools-extra/clang-tidy/add_new_check.py --update-docs'.
# | 
# `-----------------------------
# RUN: at line 2
diff --strip-trailing-cr /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang-tools-extra/test/clang-tidy/infrastructure/../../../docs/clang-tidy/checks/list.rst /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/clang/tools/extra/test/clang-tidy/infrastructure/Output/update-checks-list.test.tmp.clang-tidy-checks-list.rst
# executed command: diff --strip-trailing-cr /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang-tools-extra/test/clang-tidy/infrastructure/../../../docs/clang-tidy/checks/list.rst /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/clang/tools/extra/test/clang-tidy/infrastructure/Output/update-checks-list.test.tmp.clang-tidy-checks-list.rst
# .---command stdout------------
# | *** /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang-tools-extra/test/clang-tidy/infrastructure/../../../docs/clang-tidy/checks/list.rst
# | --- /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/tools/clang/tools/extra/test/clang-tidy/infrastructure/Output/update-checks-list.test.tmp.clang-tidy-checks-list.rst
# | ***************
# | *** 35,140 ****
# |   .. csv-table::
# |      :header: "Name", "Offers fixes"
# |   
# | -    :doc:`abseil-cleanup-ctad <abseil/cleanup-ctad>`, "Yes"
# | -    :doc:`abseil-duration-addition <abseil/duration-addition>`, "Yes"
# |      :doc:`abseil-duration-comparison <abseil/duration-comparison>`, "Yes"
# |      :doc:`abseil-duration-conversion-cast <abseil/duration-conversion-cast>`, "Yes"
# |      :doc:`abseil-duration-division <abseil/duration-division>`, "Yes"
# | -    :doc:`abseil-duration-factory-float <abseil/duration-factory-float>`, "Yes"
# |      :doc:`abseil-duration-factory-scale <abseil/duration-factory-scale>`, "Yes"
# |      :doc:`abseil-duration-subtraction <abseil/duration-subtraction>`, "Yes"
# |      :doc:`abseil-duration-unnecessary-conversion <abseil/duration-unnecessary-conversion>`, "Yes"
# |      :doc:`abseil-faster-strsplit-delimiter <abseil/faster-strsplit-delimiter>`, "Yes"
# | -    :doc:`abseil-no-internal-dependencies <abseil/no-internal-dependencies>`,
# | -    :doc:`abseil-no-namespace <abseil/no-namespace>`,
# | -    :doc:`abseil-redundant-strcat-calls <abseil/redundant-strcat-calls>`, "Yes"
# | -    :doc:`abseil-str-cat-append <abseil/str-cat-append>`, "Yes"
# |      :doc:`abseil-string-find-startswith <abseil/string-find-startswith>`, "Yes"
# |      :doc:`abseil-string-find-str-contains <abseil/string-find-str-contains>`, "Yes"
# | -    :doc:`abseil-time-comparison <abseil/time-comparison>`, "Yes"
# |      :doc:`abseil-time-subtraction <abseil/time-subtraction>`, "Yes"
# |      :doc:`abseil-unchecked-statusor-access <abseil/unchecked-statusor-access>`,
# |      :doc:`abseil-upgrade-duration-conversions <abseil/upgrade-duration-conversions>`, "Yes"
# | -    :doc:`altera-id-dependent-backward-branch <altera/id-dependent-backward-branch>`,
# | -    :doc:`altera-kernel-name-restriction <altera/kernel-name-restriction>`,
# |      :doc:`altera-single-work-item-barrier <altera/single-work-item-barrier>`,
# |      :doc:`altera-struct-pack-align <altera/struct-pack-align>`, "Yes"
# |      :doc:`altera-unroll-loops <altera/unroll-loops>`,
...

```

</details>

https://github.com/llvm/llvm-project/pull/210466