Add issue template and other fixes

Author: mosuem

.github/ISSUE_TEMPLATE/timing.md

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

pkgs/timing/pubspec.yaml

@@ -3,7 +3,7 @@ version: 1.0.2-wip
 description: >-
   A simple package for tracking the performance of synchronous and asynchronous
   actions.
-repository: https://github.com/dart-lang/timing
+repository: https://github.com/dart-lang/tools/tree/main/pkgs/timing
 
 environment:
   sdk: ^3.4.0