Add issue template and other fixes

Author: mosuem

.github/ISSUE_TEMPLATE/lints.md

@@ -0,0 +1,5 @@
+---
+name: "package:lints"
+about: "Create a bug or file a feature request against package:lints."
+labels: "package:lints"
+---

pkgs/lints/pubspec.yaml

@@ -3,7 +3,7 @@ version: 5.1.1
 description: >
   Official Dart lint rules. Defines the 'core' and 'recommended' set of lints
   suggested by the Dart team.
-repository: https://github.com/dart-lang/lints
+repository: https://github.com/dart-lang/core/tree/main/pkgs/lints
 
 topics:
   - analysis