[Chapel Merge] Updating documentation to state that list.find ret

Branch: refs/heads/main
Revision: 88f4b7e
Author: slnguyen
Link: Unavailable
Log Message:

Merge pull request #19096 from chapel-lang/list-find-doc

Updating documentation to state that list.find returns -1 for an empty list.

[trivial change, not reviewed]

Modified Files:
M modules/standard/List.chpl

Compare: https://github.com/chapel-lang/chapel/compare/fc506668998f...88f4b7edfdda