[TASK] Restore information from migration section

That was still linked from these files

Documentation/WritingDocForExtension/FAQ.rst

@@ -34,7 +34,7 @@ Why Does the Documentation not provide a title?
 .. image:: /Images/missing-title.png
    :class: with-shadow
 
-Refer to :ref:`migrate-necessary-steps` in order to fix this issue.
+Refer to :ref:`migrate` in order to fix this issue.
 
 You must add the project title to your :file:`Settings.cfg`:
 
@@ -65,7 +65,6 @@ How do I find my new rendered documentation?
 There are several possibilities:
 
 #. Search for the extension on https://docs.typo3.org/Home/Extensions.html.
-#. Or, create URL manually, see :ref:`migrate-url-structure`.
 #. Or, if it was just rerendered, the URL will be referenced from https://intercept.typo3.com/admin/docs/deployments.
    The column **Branch** contains the link.
 

Documentation/WritingDocForExtension/Index.rst

@@ -109,6 +109,46 @@ Creating extension documentation using the sample manual
    That way others can report issues and assist you by creating change requests to help
    improve both the extensions documentation and the code.
 
+Version numbers
+===============
+
+docs.typo3.org does no longer show three level version numbers in form of ``Major.Minor.Patch``.
+Only the first two levels are shown ``Major.Minor``.
+
+This reduces the amount of documentation while keeping relevant information,
+as patch levels should not introduce breaking changes or new features.
+
+.. index:: Rendering; Branches
+.. _migrate-branches:
+.. _supported-branches:
+
+Supported branches
+==================
+
+The rendering supports two branches within repositories:
+
+``main`` / ``master``
+   Should contain the current development state, used for upcoming release.
+   Every push to these branches triggers a new rendering, available at
+   :samp:`https://docs.typo3.org/p/<vendor>/<package>/main/en-us/`.
+
+   Both branch names are supported, but result in the same URL.
+   Please use ``main``, ``master`` is only supported for backward compatibility.
+
+``documentation-draft``
+   Should contain a draft of the documentation.
+   Every push to this branch triggers a new rendering, available at
+   :samp:`https://docs.typo3.org/p/<vendor>/<package>/draft/en-us/`
+   (same URL as main, except *main* is replaced by *draft*).
+
+
+   This is not indexed by search engines. This branch can be used to test
+   rendering before releasing a new version of an extension.
+
+   In order to test a different rendering, remove the branch, and create it
+   again.
+
+
 .. toctree::
    :maxdepth: 1
    :hidden: