feat: Add Github Issue Form (#9522)

Signed-off-by: Siddharth <smishra1605@gmail.com>

.github/ISSUE_TEMPLATE/enhancement.md

@@ -1,14 +0,0 @@
----
-name: Enhancement request
-about: As a developer, I want to make an enhancement for Milvus
-title: ''
-labels: kind/enhancement
-assignees: ''
-
----
-
-<!-- Please state your issue using the following template and, most importantly, in English. -->
-#### What would you like to be added:
-
-#### Why is this needed:
-

.github/ISSUE_TEMPLATE/enhancement.yaml

@@ -0,0 +1,37 @@
+name: Enhancement request
+description: As a developer, I want to make an enhancement for Milvus
+title: "[Enhancement]: "
+labels: [kind/enhancement]
+body:
+- type: markdown
+  attributes:
+    value: |
+      Thanks for taking the time to request/suggest an enhancement for Milvus! Please fill the form in English!
+- type: checkboxes
+  attributes:
+    label: Is there an existing issue for this?
+    description: Please search to see if an issue related to this already exists.
+    options:
+    - label: I have searched the existing issues
+      required: true
+- type: textarea
+  attributes:
+    label: What would you like to be added?
+    description: A concise description of what you're expecting/suggesting.
+    placeholder: |
+      I would like to suggest/request a feature that's like...
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Why is this needed?
+    description: A concise description of the reason/motivation
+  validations:
+    required: false
+- type: textarea
+  attributes:
+    label: Anything else?
+    description: |
+      Links? References? Screenshots? Anything that will give us more context about this!
+  validations:
+    required: false