Create Bug_report.md

Author: petecooper

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -0,0 +1,21 @@
+---
+name: Bug report
+about: Create a report to help us improve Textpattern's default theme.
+
+---
+
+### Expected behaviour
+
+{Please write here}
+
+### Actual behaviour
+
+{Please write here}
+
+### Steps to reproduce
+
+{Please write here}
+
+#### Additional information
+
+Browser version and operating system: {Please write here}