[clang-tools-extra] [clang-tidy][doc][NFC] extract common global options in doc (PR #119842)

[Carlos Galvez via cfe-commits]

================
@@ -0,0 +1,21 @@
+==============
+Global Options
+==============
+
+Some options apply to multiple checks. This page lists all the available
+globally options.
+
+.. option:: IncludeStyle
+
+   A string specifying which include-style is used, `llvm` or `google`. Default
+   is `llvm`.
+
+.. option:: IgnoreMacros
+
+   If set to `true`, the check will not give warnings inside macros. Default
+   is `true`.
+
+.. option:: StrictMode
----------------
carlosgalvezp wrote:

This option does not have any meaning in this context. Therefore I believe it should be kept local.



https://github.com/llvm/llvm-project/pull/119842