Add PR template

Signed-off-by: Carlisia <[email protected]>

.github/workflows/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,8 @@
+#### Special notes for your reviewer:
+
+#### Checklist
+[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]
+- [ ] [DCO](https://github.com/helm/charts/blob/master/CONTRIBUTING.md#sign-your-work) signed
+- [ ] Chart Version bumped
+- [ ] Variables are documented in the README.md
+- [ ] Title of the PR starts with chart name (e.g. `[velero]`)