Add bug issue template

Author: konradpabjan

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,42 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**Which version of the action are you using?**
+
+- [ ] `v1`
+- [ ] `v2`
+- [ ] Some other tag (such as `v2.0.1` or `master`)
+
+**Environment**
+- [ ] self-hosted
+- [ ] Linux
+- [ ] Windows
+- [ ] Mac
+
+**Python Versions**
+Please list all of the effected versions of Python (`3.8.2`, etc.)
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Run/Repo Url**
+If applicable, and if your repo/run is public, please include a URL so it is easier for us to investigate.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Additional context**
+Add any other context about the problem here.