[Chapel Merge] Consider the deprecated keyword as an alternative

Branch: refs/heads/main
Revision: 25da47d
Author: gbtitus
Log Message:

Merge pull request #18373 from gbtitus/deprDocAdjustment

Consider the deprecated keyword as an alternative to compilerWarning().

(Reviewed by @lydia-duncan.)

Update our internal deprecation documentation for new, handy keyword!

Modified Files:
M doc/rst/developer/bestPractices/Deprecation.rst

Compare: https://github.com/chapel-lang/chapel/compare/f519dec800e8...25da47dc7ba9