Flesh out the ISSUE_TEMPLATE.md file a bit

Providing some examples of the kinds of info that are helpful in
reproducing bugs in OPA.

Signed-off-by: Torin Sandall <torinsandall@gmail.com>

ISSUE_TEMPLATE.md

@@ -1,13 +1,25 @@
-# Expected Behavior
+Thanks for opening an issue to request a feature or file a bug! If you provide some
+basic information it helps us address problems faster.
 
+# Expected Behavior
 
 # Actual Behavior
 
-
 # Steps to Reproduce the Problem
 
-  1.
-  2.
-  3.
+If this is a bug report please provide as much detail as possible so that we can
+reproduce the problem. Examples:
+
+* OPA version
+* Example query, input, data, and policy that OPA was given
+* Example output that OPA returned
+* For server and CLI, the flags/configuration that you provided to OPA
+* For server, any relevant log messages from OPA
+* For Go and Wasm, the arguments you invoked OPA with
 
 # Additional Info
+
+Any additional information you think might be helpful. Examples include the environment
+where OPA was running (e.g., if inside Kubernetes, what resource limits did you configure
+OPA with?), how long OPA had been running for, what was happening around the time
+when you identified the problem, etc.