The version of mermaid included in Obsidian is indeed some versions behind the mermaid library itself. I’m not sure how to get which version is included in Obsidian, but if you find that you should be able to deduct which types of diagrams are available. AFAIK at least the timeline and mindmap diagram types are as of today not included in Obsidian.
The Harvard Crimson: The Scholarly Mapmaker Wants 'True Portrait of Mother Earth'
It's quite easy to make a map. Even if you can't draw. Simply sketch in a few lines on a piece of paper, identify some important intersections and checkpoints, and that's it. For indicating directions ...