Add GitHub PR and issue templates (#76)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,28 @@
+---
+name: Bug report
+about: Create a report to help us improve Wire
+
+---
+
+You can use `go bug` to have a cool, automatically filled out bug template, or
+fill out the template below.
+
+### Describe the bug
+
+A clear and concise description of what the bug is.
+
+### To Reproduce
+
+Steps to reproduce the behavior.
+
+## Expected behavior
+
+A clear and concise description of what you expected to happen.
+
+### Version
+
+Which version of Wire are you seeing the bug with?
+
+### Additional context
+
+Add any other context about the problem here.