doc: issue template for bug reports (#998)

Signed-off-by: Devdutt Shenoi <[email protected]>

Author: Devdutt Shenoi

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,27 @@
+---
+name: Bug Report
+about: Create a bug report for Parseable.
+labels: bug
+---
+<!--
+Thank you for filing a bug report! 🐛 Please provide a short summary of the bug,
+along with any information you feel relevant to replicating the bug.
+-->
+
+`/about` output:
+<!--
+Accessible from `https://{parseable-instance}/api/v1/about` with curl or provide
+screenshot of about modal in dashboard.
+-->
+```json
+{
+  "version": "...",
+  ...
+}
+```
+
+Description:
+<!--
+What was your expectation, provide us a brief about the same, before describing
+the observed behaviour and explaining why you believe this is a bug.
+-->