[clang-format][docs] mark new clang-format configuration options base…

…d on which version they would GA

Sometimes I see people unsure about which options they can use in specific versions of clang-format because
https://clang.llvm.org/docs/ClangFormatStyleOptions.html points to the latest and greatest versions.

The reality is this says its version 13.0, but actually anything we add now, will not be in 13.0 GA but
instead 14.0 GA (as 13.0 has already been branched).

How about we introduce some nomenclature to the Format.h so that we can mark which options in the
documentation were introduced for which version?

Reviewed By: HazardyKnusperkeks

Differential Revision: https://reviews.llvm.org/D110432