chore: add feature request template (vuejs#4490)

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,35 @@
+name: "\U0001F680 New feature proposal"
+description: Suggest an idea for this project
+labels: ["feature request"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+       **Before You Start...**
+
+        This form is only for submitting feature requests. If you have a usage question
+        or are unsure if this is really a bug, make sure to:
+
+        - Ask on **#language-tools** channel on our [Discord Server](https://discord.gg/vue)
+        - Ask on [GitHub Discussions](https://github.com/vuejs/language-tools/discussions)
+
+        Also try to search for your issue - another user may have already requested something similar!
+
+  - type: textarea
+    id: problem-description
+    attributes:
+      label: What problem does this feature solve?
+      description: |
+        Explain your use case, context, and rationale behind this feature request. More importantly, what is the **end user experience** you are trying to build that led to the need for this feature?
+      placeholder: Problem description
+    validations:
+      required: true
+  - type: textarea
+    id: proposed-solution
+    attributes:
+      label: What does the proposed solution look like?
+      description: |
+        Describe how you propose to solve the problem.
+      placeholder: Proposed solution
+    validations:
+      required: true