fix: put issue templates inside .github folder (#761)

.github/ISSUE_TEMPLATE/3.feature_request.yml

@@ -0,0 +1,28 @@
+name: Feature Request
+description: Create a feature request for the Next.js core
+labels: 'template: story'
+body:
+  - type: markdown
+    attributes:
+      value: Thanks for taking the time to file a feature request! Please fill out this form as completely as possible.
+  - type: markdown
+    attributes:
+      value: 'Feature requests will be converted to the GitHub Discussions "Ideas" section.'
+  - type: textarea
+    attributes:
+      label: Describe the feature you'd like to request
+      description: A clear and concise description of what you want and what your use case is.
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Describe the solution you'd like
+      description: A clear and concise description of what you want to happen.
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Describe alternatives you've considered
+      description: A clear and concise description of any alternative solutions or features you've considered.
+    validations:
+      required: true