Add an issue template file. (#192)

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,22 @@
+Please answer these questions before submitting your issue. Thanks!
+
+### What version of pprof are you using?
+
+If you are using pprof via `go tool pprof`, what's your `go env` output?
+If you run pprof from Github, what's the Git revision?
+
+
+### What operating system and processor architecture are you using?
+
+
+### What did you do?
+
+If possible, provide a recipe for reproducing the error.
+Attaching a profile you are trying to analyze is good.
+
+
+### What did you expect to see?
+
+
+### What did you see instead?
+