add issue_template

.github/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,21 @@
+---
+name: Bug report
+about: Report an issue or unexpected behaviour with Artplayer
+---
+
+### Expected behaviour
+
+### Actual behaviour
+
+### Steps to reproduce
+
+### Environment
+
+- Browser:
+- Version:
+- Operating System:
+- Version:
+
+### Console errors (if any)
+
+### Link to where the bug is happening