Update feature_request.md

Add preflight checks

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,6 +7,14 @@ assignees: ''
 
 ---
 
+## Preflight Checklist
+
+Please ensure you've completed all of the following.
+
+- [ ] I agree to follow the [Code of Conduct](https://github.com/codeaffen/phpipam-ansible-modules/blob/develop/CODE_OF_CONDUCT.md).
+- [ ] I have searched the [issue tracker](https://github.com/codeaffen/phpipam-ansible-modules/issues) for a feature requests that matches the one I want to file, without success.
+- [ ] I only submit one single feature per feature request.
+
 **Is your feature request related to a problem? Please describe.**
 A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]