chore: add new feature issue template

.github/ISSUE_TEMPLATE/new-feature.md

@@ -0,0 +1,24 @@
+name: New Feature / Enhancement
+description: Propose a new idea to be implemented
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to propose a new feature / enhancement idea.
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: Include as much info as possible, including mockups / screenshots if available.
+      placeholder: Description
+    validations:
+      required: true
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Code of Conduct
+      description: By submitting this request, you agree to follow our [Code of Conduct](https://github.com/ietf-tools/.github/blob/main/CODE_OF_CONDUCT.md).
+      options:
+        - label: I agree to follow the [IETF's Code of Conduct](https://github.com/ietf-tools/.github/blob/main/CODE_OF_CONDUCT.md)
+          required: true