Add issue templates

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,32 @@
+---
+name: Bug report
+about: I found a bug in Mango!
+title: "[Bug Report]"
+labels: bug
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Environment (please complete the following information):**
+ - OS: [e.g. Ubuntu 18.04]
+ - Browser [e.g. chrome, safari, if applicable]
+ - Mango Version [e.g. v0.1.0]
+
+**Docker (if you are running Mango in a Docker container)**
+- The `docker-compose.yml` file you are using
+
+**Additional context**
+Add any other context about the problem here. Add screenshots if applicable.