Git: Add CMake command to issue template

ISSUE_TEMPLATE.md

@@ -17,6 +17,14 @@ Fill out the sections and checklist below (add text at the end of each line).
 
 ## Background Information / Reproduction Steps
 
+Used CMake command line:
+
+<!-- Include all options here, which you modified or used for your build -->
+
+```bash
+cmake -DUA_ENABLE_FULL_NS0=<YOUR_OPTION> <ANY_OTHER_OPTIONS> ..
+```
+
 ## Checklist
 
 Please provide the following information: