docs: Add minimap configuration section

[MrSubidubi]

This PR adds some documentation about the minimap to the official docs.

Please note: The current preview release notes refer to the minimap PR for configuration options. However, font_size and width were removed as settings after some discussion but are still referenced in the PR description, which might be misleading. On the other hand, some of the available configuration options are not listed in the PR description. It might be better to refer to the docs or the default settings in order to avoid confusion.

Release Notes:

• N/A