docs(helm): add contributing guidelines for helm chart (#1486)

Signed-off-by: Ludovic Ortega <ludovic.ortega@adminafk.fr>

CONTRIBUTING.md

@@ -58,12 +58,27 @@ All help is welcome and greatly appreciated! If you would like to contribute to
 
    - Be sure to follow both the [code](#contributing-code) and [UI text](#ui-text-style) guidelines.
    - Should you need to update your fork, you can do so by rebasing from `upstream`:
+
      ```bash
      git fetch upstream
      git rebase upstream/develop
      git push origin BRANCH_NAME -f
      ```
 
+### Helm Chart  
+
+Tools Required:
+
+- [Helm](https://helm.sh/docs/intro/install/)  
+- [helm-docs](https://github.com/norwoodj/helm-docs)  
+
+Steps:
+
+1. Make the necessary changes.  
+2. Test your changes.  
+3. Update the `version` in `charts/jellyseerr-chart/Chart.yaml` following [Semantic Versioning (SemVer)](https://semver.org/).  
+4. Run the `helm-docs` command to regenerate the chart's README.
+
 ### Contributing Code
 
 - If you are taking on an existing bug or feature ticket, please comment on the [issue](https://github.com/fallenbagel/jellyseerr/issues) to avoid multiple people working on the same thing.