Add information to unreleased and user doc for upcoming changes which require manual effort during the migration

Author: ArBridgeman

doc/changes/unreleased.md

@@ -1,5 +1,18 @@
 # Unreleased
 
+## Summary
+
+With #420, any GitHub repos using the PTB for **documentation** will also need to 
+reconfigure the GitHub Pages settings for each repo:
+1. Go to the affected repo's GitHub page
+2. Select 'Settings'
+3. Scroll down & select 'Pages'
+4. Within the 'Build and deployment' section, change 'Source' to 'GitHub Actions'.
+
+This should also create a 'github-pages' environment, if it does not yet exist.
+For most repos using the PTB, the updating of the github pages only happens when a
+PR is merged to main, so please check post-merge that it worked as expected.
+
 ## ⚒️ Refactorings
 
 * [#412](https://github.com/exasol/python-toolbox/issues/392):  Refactored pre commit hook package version.py into nox task

doc/user_guide/getting_started.rst

@@ -179,7 +179,17 @@ forward, and you just can use the example *noxfile.py* below.
 
 .. _toolbox tasks:
 
-7. Go 🥜
+7. Setup for deploying documentation (optional)
++++++++++++++++++++++++++++++++++++++++++++++++
+Within the `gh-pages.yml`, we use the GitHub `upload-pages-artifact` and `deploy-pages`
+actions. In order to properly deploy your pages, you'll need to reconfigure the GitHub
+Pages settings for the repo:
+1. Go to the affected repo's GitHub page
+2. Select 'Settings'
+3. Scroll down & select 'Pages'
+4. Within the 'Build and deployment' section, change 'Source' to 'GitHub Actions'.
+
+8. Go 🥜
 +++++++++++++
 You are ready to use the toolbox. With *nox -l* you can list all available tasks.