docs: move docs branch sections from readme to contrib guide

docs/CONTRIBUTING.md

@@ -229,7 +229,75 @@ Add "WIP" (Work in Progress) or "Draft" to the title if the PR is not yet ready
    git branch -d <branch-name>
    ```
 
-## Developer Certification of Origin (DCO)
+## Choosing the correct branch when contributing
+
+New writing goes to the `main` branch and can be viewed on the Releases -> development dropdown menu.
+We have staging and production levels for our documentation which are as follows:
+
+* **Latest:** official documentation of the current Keptn release
+  * [link](https://lifecycle.keptn.sh):
+      This is the build of the `page` branch.
+
+* **Development:** documentation being staged for the next Keptn release
+  * [link](https://main.lifecycle.keptn.sh):
+   This is the latest build of the `main` branch.
+
+* **Previous versions:** documentation for earlier releases.
+   These are listed at [link](https://github.com/keptn/lifecycle-toolkit/tree/page/docs/content/en).
+
+* **Contribute:** current version of the "Contribute" guide
+   that is available from a tab on the documentation site.
+
+Let's take a look what happens when your changes are merged in `main` and `page` branch respectively.
+
+## Latest -- Official documentation (Production)
+
+This set of documentation pertains to the latest KLT release and resides within an
+isolated branch known as `page`.
+When a new version of KLT is launched, the contents of the `development`
+branch are rolled into this branch.
+Additionally, it's important to recognize that any
+document changes made using the "Edit this page" feature are seamlessly integrated into this branch.
+
+This uses the `latest` label so that links to a doc page
+remain valid across software and documentation updates.
+
+* build: on each push to `page` with documentation changes
+* build-environment: production
+* config folder: [production](./config/production/)
+
+A new version is generated when we push the `main` branch to production to release a new version of the docs page.
+This means, that the content of the old version on the `page` branch will be copied over
+to a `docs-<version>` folder and the new version will be pushed into the `docs` folder.
+This way, no changes or older versions get overwritten.
+
+## Development documentation (Staging)
+
+This page contains the documentation being staged for the next Keptn release.
+It contains information about new and changed features and functionality
+as well as general documentation improvements.
+It is built regularly and can be easily accessed from the `Releases` tab on the documentation site.
+
+* build: on each push to `main` with documentation changes
+   from a user's local branch, from the github editor, or from codespaces
+* build-environment: main
+* config folder: [main](./config/staging/)
+
+This version represents the pre-release iteration of the documentation for the upcoming Keptn release.
+Pull requests originating from a user's local branch, the GitHub editor, or codespaces are merged into this branch.
+
+When a new Keptn version is officially launched, this branch is elevated to the status of `latest`.
+In exceptional cases, a pull request that includes vital documentation enhancements may be discreetly
+advanced to `latest` without the need for a software release.
+
+## Previous Versions
+
+Keptn documentation is versioned.
+By default, the version for the current Keptn release
+is displayed on the documentation page but users can select other versions from the Releases tab.
+The previous versions of the Keptn Documentation are available [here](https://github.com/keptn/lifecycle-toolkit/tree/page/docs/content/en).
+
+### Developer Certification of Origin (DCO)
 
 All commits must be accompanied by a DCO sign-off.
  See