Add step to version Loki docs during public release process. (#3277)

* Add step to version Loki docs during public release process.

* Update docs/sources/maintaining/release.md

Co-authored-by: Cyril Tovena <cyril.tovena@gmail.com>

Co-authored-by: Cyril Tovena <cyril.tovena@gmail.com>

docs/sources/maintaining/release.md

@@ -99,3 +99,14 @@ Once the previous two steps are completed, you can publish your draft!
 1. Optionally, have other team members review the release draft so you feel
    comfortable with it.
 1. Publish the release!
+
+## Versioning Loki docs on Grafana Website
+
+Loki docs are versioned. Follow the below steps to version Loki docs for this release.
+
+1. Clone Grafana website [repo] (https://github.com/grafana/website)
+1. Create new branch `git checkout -b loki-v1.2.3` (replace `v1.2.3` with current release version)
+1. Run `make project-doc-release`
+1. It prompts for two things. `Project name` and `version`. Project name is `loki` and version is current release version.
+1. Docs will be generated for this release.
+1. Create PR and Merge it after approval.