readme: document mike usage

Author: Pablo Panero

README.md

@@ -6,11 +6,126 @@
 
 InvenioRDM user documentation web site.
 
-## Running
+## Run the docs locally
 
 ```console
 $ mkvirtualenv docs-invenio-rdm
 $ pip install -r requirements.txt
-$ mkdocs serve
+$ mkdocs serve # mike serve if you are using mike for versioning
 $ firefox http://127.0.0.1:8000
 ```
+
+## Set up versioning
+
+This means having `/x.y.z/` at the end of the url to point to a specific release
+version. You can also set up aliases to have `latest` or any desire string tag.
+
+### Initial setup, onte time operations
+
+#### Create the documentation branch
+
+Create and orphan branch called `gh-pages`. This name is mandatory to avoid
+extra configuration in mike and GitHub.
+
+``` console
+$ git checkout master
+$ git checkout --orphan gh-pages
+$ rm -rf ./*
+$ git rm -r ./*
+$ git commit -m "initial commit: index redirect"
+$ git push origin gh-pages
+```
+
+Why an orphan branch? In order to separate the build documentation from the
+source of it.
+
+#### Create a latest redirection
+
+By default GitHub pages serve the `index.html` file from the root directory.
+Mike does not build one by default, and we would like the documentation site
+to point to `/latest`. We can use the `set-default` command:
+
+``` console
+$ mike set-default latest -p
+```
+
+#### Install [mike](https://github.com/jimporter/mike)
+
+Create a new branch (to do a PR from) and install mike's extras:
+
+``` console
+$ git checkout master
+$ git checkout -b versioning
+$ mike install-extras
+```
+
+Add and commit the changes. This will include formating of the `mkdocs.yaml`
+plus some additions. As well as the css and js files needed for mike.
+
+``` console
+$ git add -p
+$ git add docs/css/
+$ git add docs/js/
+$ git commit -m "versioning: add mikes extras"
+$ git push origin versioning
+```
+
+**Note**: You might want to add `mike` to the requiresments.txt although it is
+not necesary for the build itself.
+
+### Operations
+
+#### Deploy!
+
+First of all fetch all branches to help mike sync. It does a great job on
+this, but is better to be sure.
+
+``` console
+$ git fetch --all
+```
+
+Then you need to build the new documentation. It is recommended to
+**not use** `-p` first. That way you can check the deployment (gh-pages
+branch) locally and then push upstream.
+
+``` console
+$ mike deploy 0.7.0 latest
+$ mike serve
+```
+
+Then deploy it (push it to gh-pages), if you want to update the aliases, for
+example to release a new latest. Use the `-u` option when deploying.
+
+``` console
+$ mike deploy 0.7.0 latest -p -u
+```
+
+**Warning**: after deploying you will get the `site/` folder. There is
+no need to commit it since it will be created each time you deploy.
+
+Finally, you should tag it and push it to github so it stays versioned.
+Note that you have pushed built documentation, but if you wish to be able
+to edit it in the future you need to save its source files.
+
+``` console
+$ git tag v0.7.0
+$ git push origin v0.7.0
+```
+
+#### Editing previous versions of the documentation
+
+As mentioned above, when deploying we do not store the source files. Those
+are stored in the git tags. Therefore, to edit previous documentation we
+should edit those.
+
+Then delete the old version of the docs and re-deploy:
+
+```console
+$ git checkout 0.6.3
+$ mike delete 0.6.3 -p
+$ # Perform edits, add and commit
+$ git tag 0.6.4 # Or delete the old tag to keep it consistent with the InvenioRDM versions
+$ mike deploy 0.6.3 -p
+```
+
+More docs [here](https://github.com/jimporter/mike).