Update feature_request.md

Users will set the `suggestion` tag, while admins will update it to `enhancement` once accepted

.github/ISSUE_TEMPLATE/feature_request.md

@@ -2,7 +2,7 @@
 name: Feature Request
 about: Suggest an idea for this project
 title: "[Enhancement] "
-labels: enhancement, not-reviewed
+labels: suggestion, not-reviewed
 assignees: ''
 
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