Update feature request template: change label from 'feature-request' to 'enhancement'

Author: dermatz

.github/ISSUE_TEMPLATE/feature_request.md

@@ -2,7 +2,7 @@
 name: Feature request
 about: Suggest an idea for this project
 title: 'Feature-Request: '
-labels: feature-request
+labels: enhancement
 assignees: ''
 ---