[clang-tools-extra] [clang-tidy] Add readability-use-span-first-last check (PR #118074)

[Helmut Januschka via cfe-commits]

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@@ -0,0 +1,24 @@
+.. title:: clang-tidy - readability-use-span-first-last
+
+readability-use-span-first-last
+===============================
+
+Suggests using ``std::span::first()`` and ``std::span::last()`` member functions 
+instead of equivalent ``subspan()``. These dedicated methods were added to C++20 
+to provide more expressive alternatives to common subspan operations.
+
+Covered scenarios:
+
+=========================== ============
----------------
hjanuschka wrote:

thank you, super sorry that this is such a back n forth, but my brain seems to be wired a way to not being able to figure RST out 🙈

https://github.com/llvm/llvm-project/pull/118074