Setting up `PERSONAL_ACCESS_TOKEN`

[florence-bockting]

Description

Create a personal access token that can be used to write to the repository as part of GitHub actions.

TODOs

• create a fine-grained token with read and write access for "Contents" -> personal access token access must be enabled by the organisation's maintainer
• add token to repository secrets (Settings/Secrets and Variables/Actions/New repository secret) called PERSONAL_ACCESS_TOKEN