Add issue template to try and curb reports lacking information

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,21 @@
+With the following composer.json:
+
+```json
+{
+    ...
+}
+```
+
+When I run this command:
+
+```
+composer command -vvv (please include -vvv!)
+```
+
+I get this output:
+
+```
+
+```
+
+And I expected this to happen: