chore: Add contributing and versioning docs on helm chart (grafana#14339

)

.github/pull_request_template.md

@@ -12,5 +12,4 @@ Fixes #<issue number>
 - [ ] Title matches the required conventional commits format, see [here](https://www.conventionalcommits.org/en/v1.0.0/)
   - **Note** that Promtail is considered to be feature complete, and future development for logs collection will be in [Grafana Alloy](https://github.com/grafana/alloy). As such, `feat` PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
 - [ ] Changes that require user attention or interaction to upgrade are documented in `docs/sources/setup/upgrade/_index.md`
-- [ ] For Helm chart changes bump the Helm chart version in `production/helm/loki/Chart.yaml` and update `production/helm/loki/CHANGELOG.md` and `production/helm/loki/README.md`. [Example PR](https://github.com/grafana/loki/commit/d10549e3ece02120974929894ee333d07755d213)
 - [ ] If the change is deprecating or removing a configuration option, update the `deprecated-config.yaml` and `deleted-config.yaml` files respectively in the `tools/deprecated-config-checker` directory. [Example PR](https://github.com/grafana/loki/pull/10840/commits/0d4416a4b03739583349934b96f272fb4f685d15)

production/helm/loki/README.md

@@ -19,3 +19,14 @@ Helm chart for Grafana Loki and Grafana Enterprise Logs supporting both simple,
 | https://grafana.github.io/helm-charts | rollout_operator(rollout-operator) | 0.13.0 |
 
 Find more information in the Loki Helm Chart [documentation](https://grafana.com/docs/loki/next/installation/helm).
+
+## Contributing and releasing
+
+If you made any changes to the [Chart.yaml](https://github.com/grafana/loki/blob/main/production/helm/loki/Chart.yaml) or [values.yaml](https://github.com/grafana/loki/blob/main/production/helm/loki/values.yaml) run `make helm-doc` from the root of the repository to update the documentation and commit the changed files.
+
+#### Versioning
+
+Normally contributors need _not_ bump the version nor update the [CHANGELOG.md](https://github.com/grafana/loki/blob/main/production/helm/loki/CHANGELOG.md). A new version of the Chart will follow this cadence:
+- Automatic weekly releases
+- Releases that coincide with Loki/GEL releases
+- Manual releases when necessary (ie. to address a CVE or critical bug)

production/helm/loki/README.md.gotmpl

@@ -9,3 +9,14 @@
 {{ template "chart.requirementsSection" . }}
 
 Find more information in the Loki Helm Chart [documentation](https://grafana.com/docs/loki/next/installation/helm).
+
+## Contributing and releasing
+
+If you made any changes to the [Chart.yaml](https://github.com/grafana/loki/blob/main/production/helm/loki/Chart.yaml) or [values.yaml](https://github.com/grafana/loki/blob/main/production/helm/loki/values.yaml) run `make helm-doc` from the root of the repository to update the documentation and commit the changed files.
+
+#### Versioning
+
+Normally contributors need _not_ bump the version nor update the [CHANGELOG.md](https://github.com/grafana/loki/blob/main/production/helm/loki/CHANGELOG.md). A new version of the Chart will follow this cadence:
+- Automatic weekly releases
+- Releases that coincide with Loki/GEL releases
+- Manual releases when necessary (ie. to address a CVE or critical bug)