add template

ISSUE_TEMPLATE.md

@@ -0,0 +1,17 @@
+<!-- If you have a question or improvement suggestion rather than an actual issue/bug, pls use our forum:-->
+
+<!-- https://ask.openrouteservice.org/c/ors-->
+
+#### Here's what I did
+<!-- include request URLs, link to app.config or other relevant ifnormation -->
+
+---
+#### Here's what I got
+<!-- we :heart: json outputs -->
+
+---
+#### Here's what I was expecting
+<!-- try being as explicit as possible here so we know how to fix this issue -->
+
+---
+#### Here's what I think could be improved