new: add gitea issue template

.gitea/issue_template.yaml

@@ -0,0 +1,34 @@
+name: Package issue
+about: Report an issue for a package
+title: "<package name>: <issue desc>"
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for reporting this issue!
+  - type: textarea
+    id: explain
+    attributes:
+      label: Explain the issue
+      description: Please explain the issue you are having with the package in detail
+    validations:
+      required: true
+  - type: dropdown
+    id: repo
+    attributes:
+      label: Select a repo
+      description: Which repo are you using? (Check /etc/matt/config.ini)
+      options:
+        - Stable base repo (mptp://stable.matterlinux.xyz/base)
+        - Next base repo (mptp://next.matterlinux.xyz/base)
+        - Other (specify in the description)
+    validations:
+      required: true
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Code of conduct
+      description: By submitting this issue, you agree to follow our [Code of Conduct](https://matterlinux.xyz/wiki/conduct)
+      options:
+        - label: I understand
+          required: true