Update the Writing Lints document

The document refers to GitHub labels that have been changed. This
updates the references to be complete.

Change-Id: Ib08e3dfaf386997d6bd126708f56584b57a1f5fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/418660
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>
Auto-Submit: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/linter/doc/writing-lints.md

@@ -420,4 +420,4 @@ performing your own full `CompilationUnit` visits.
 Details are under active development.
 Feedback is most [welcome][issues]!
 
-[issues]: https://github.com/dart-lang/sdk/issues/new?assignees=&labels=area-analyzer,analyzer-linter&projects=&template=2_analyzer.md
+[issues]: https://github.com/dart-lang/sdk/issues/new?assignees=&labels=area-devexp,devexp-linter&projects=&template=2_analyzer.md