Create ISSUE_TEMPLATE.md

Author: sergey-tihon

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,30 @@
+### Description
+
+Please provide a succinct description of your issue.
+
+### Repro steps
+
+Please provide the steps required to reproduce the problem
+
+1. Step A
+
+2. Step B
+
+### Expected behavior
+
+Please provide a description of the behavior you expect.
+
+### Actual behavior
+
+Please provide a description of the actual behavior you observe. 
+
+### Known workarounds
+
+Please provide a description of any known workarounds.
+
+### Related information 
+
+* Operating system
+* Branch
+* .NET Runtime, CoreCLR or Mono Version
+* Performance information, links to performance testing scripts