[Documentation] Improve checks groups descriptions in clang-tidy/index.rst

[Eugene.Zelenko]

Summary

Use table to avoid tautology. List all existing checks groups. Use alphabetical order.

Recent Sphinx documentation claims that syntax is valid, but will be good idea to test it with actually used Sphinx.

Will be good idea if native English speaker will check wording.

[alexfh]

Awesome! Looks good!

clang-tools-extra/trunk/docs/clang-tidy/index.rst

 
 The ``-list-checks`` option lists all the enabled checks. When used without
 ``-checks=``, it shows checks enabled by default. Use ``-checks=*`` to see all
 available checks or with any other value of ``-checks=`` to see which checks are
 enabled by this value.
 
 There are currently the following groups of checks:
 
-* Checks related to the LLVM coding conventions have names starting with
-  ``llvm-``.
-
-* Checks related to the Google coding conventions have names starting with
-  ``google-``.
-
-* Checks named ``modernize-*`` advocate the usage of modern (currently "modern"
+====================== =========================================================
+Name prefix            Description
+====================== =========================================================
+``boost-``             Checks related to Boost library.
+``cert-``              Checks related to CERT Secure Coding Guidelines.
+``cppcoreguidelines-`` Checks related to C++ Core Guidelines.
+``clang-analyzer-``    Clang Static Analyzer checks.
+``google-``            Checks related to the Google coding conventions.
+``llvm-``              Checks related to the LLVM coding conventions.
+``misc-``              Checks that we didn't have a better category for.
+``modernize-``         Checks that advocate usage of modern (currently "modern"
                        means "C++11") language constructs.
-
-* The ``readability-`` checks target readability-related issues that don't
+``mpi-``               Checks related to MPI (Message Passing Interface).
+``performance-``       Checks that target performance-related issues.
+``readability-``       Checks that target readability-related issues that don't
                        relate to any particular coding style.
-
-* Checks with names starting with ``misc-`` the checks that we didn't have a
-  better category for.
-
-* Clang static analyzer checks are named starting with ``clang-analyzer-``.
-
-* Checks related to Boost library starts with ``boost-``. 
-  
+====================== =========================================================
 Clang diagnostics are treated in a similar way as check diagnostics. Clang
 diagnostics are displayed by clang-tidy and can be filtered out using
 ``-checks=`` option. However, the ``-checks=`` option does not affect
 compilation arguments, so it can not turn on Clang warnings which are not
 already turned on in build configuration. The ``-warnings-as-errors=`` option
 upgrades any warnings emitted under the ``-checks=`` flag to errors (but it
 does not enable any checks itself).