Improve contribution part of this repository (#328)

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/328
Reviewed-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: justusbunsi <justusbunsi@noreply.gitea.io>
Co-committed-by: justusbunsi <justusbunsi@noreply.gitea.io>

.gitea/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,41 @@
+<!--
+ Before you open the request please review the following guidelines and tips to help it be more easily integrated:
+
+ - Describe the scope of your change - i.e. what the change does.
+ - Describe any known limitations with your change.
+ - Please run any tests or examples that can exercise your modified code.
+
+ Thank you for contributing! We will try to review, test and integrate the change as soon as we can.
+ -->
+
+### Description of the change
+
+<!-- Describe the scope of your change - i.e. what the change does. -->
+
+### Benefits
+
+<!-- What benefits will be realized by the code change? -->
+
+### Possible drawbacks
+
+<!-- Describe any known limitations with your change -->
+
+### Applicable issues
+
+<!-- Enter any applicable Issues here (You can reference an issue using #). Please remove this section if there is no referenced issue. -->
+  - fixes #
+
+### Additional information
+
+<!-- If there's anything else that's important and relevant to your pull request, mention that information here. Please remove this section if it remains empty. -->
+
+### ⚠ BREAKING
+
+<!-- If there's a breaking change, please shortly describe in which way users are affected and how they can mitigate it. If there are no breakings, please remove this section. -->
+
+### Checklist
+
+<!-- [Place an '[X]' (no spaces) in all applicable fields. Please remove unrelated fields.] -->
+
+- [ ] Parameters are documented in the `values.yaml` and added to the `README.md` using [readme-generator-for-helm](https://github.com/bitnami-labs/readme-generator-for-helm)
+- [ ] Breaking changes are documented in the `README.md`