chore(gitea): migrate issue templates

.gitea/ISSUE_TEMPLATE/bug.yaml

@@ -1,6 +1,7 @@
 name: 🐛 Bug Report
-description: Report a bug or unexpected behavior
+about: Report a bug or unexpected behavior
 title: '🐛 [BUG]: '
+ref: main
 body:
   - type: textarea
     id: information

.gitea/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,2 @@
+# Require one of the structured issue templates below.
+blank_issues_enabled: false

.gitea/ISSUE_TEMPLATE/feature.yaml

@@ -1,6 +1,7 @@
 name: 💡 Enhancement
-description: Suggest a new feature or improvement
+about: Suggest a new feature or improvement
 title: '💡 [ENHANCEMENT]: '
+ref: main
 body:
   - type: textarea
     id: description

.gitea/ISSUE_TEMPLATE/improvement.yaml

@@ -1,6 +1,7 @@
 name: ⚙️ Improvement
-description: Suggest an improvement to existing functionality, code quality, or performance
+about: Suggest an improvement to existing functionality, code quality, or performance
 title: '⚙️ [Improvement]: '
+ref: main
 body:
   - type: textarea
     id: context

.github/ISSUE_TEMPLATE/config.yml

@@ -1 +0,0 @@
-blank_issues_enabled: false