[clang-tools-extra] [clang-tidy] align all help message in run-clang-tidy (PR #96199)

[Julian Schmidt via cfe-commits]

https://github.com/5chmidti commented:

When you add a `.` to make the help messages sentences, then you might want to capitalize the first word as well.

https://github.com/llvm/llvm-project/pull/96199