fix: use yaml, not yml YAML file extension

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,28 +0,0 @@
-name: Feature Request
-description: Suggest a feature
-title: "feat: "
-labels: [enhancement]
-body:
-  - type: checkboxes
-    attributes:
-      label: Prerequisites
-      options:
-        - label: I have searched [existing issues](https://github.com/barrettruth/diffs.nvim/issues)
-          required: true
-
-  - type: textarea
-    attributes:
-      label: Problem
-      description: What problem does this solve?
-    validations:
-      required: true
-
-  - type: textarea
-    attributes:
-      label: Proposed solution
-    validations:
-      required: true
-
-  - type: textarea
-    attributes:
-      label: Alternatives considered