chore: add issue templates (#521)

Signed-off-by: Aaron Pham <contact@aarnphm.xyz>

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,35 @@
+name: 🚀 Feature Request
+description: Submit a proposal/request for new Avante feature.
+title: 'feature: '
+labels: ['new-feature', 'enhancement']
+body:
+  - type: textarea
+    id: feature-request
+    validations:
+      required: true
+    attributes:
+      label: Feature request
+      description: |
+        A clear and concise description of the feature request.
+      placeholder: |
+        I would like it if...
+  - type: textarea
+    id: motivation
+    validations:
+      required: false
+    attributes:
+      label: Motivation
+      description: |
+        Please outline the motivation for this feature request. Is your feature request related to a problem? e.g., I'm always frustrated when [...].
+        If this is related to another issue, please link here too.
+        If you have a current workaround, please also provide it here.
+      placeholder: |
+        This feature would solve ...
+  - type: textarea
+    id: other
+    attributes:
+      label: Other
+      description: |
+        Is there any way that you could help, e.g. by submitting a PR?
+      placeholder: |
+        I would love to contribute ...