Making Mermaid JS more useful

[zeekhuge]

Thank you for all you efforts in this repo @tommoor .

I have been playing around with Mermaid-JS on outline, for quite some time and have seen following limitations:

1. Unable to do horizontal scroll - and as you add some 20-40 nodes to the graph, it tries to - sorta zoom out on itself - in an attempt to fit everything. A horizontal scroll would fix that. There's an old related question here - Hope have a horizontal scrollbar when too many nodes in graph mermaid-js/mermaid#652
2. I encountered errors related to Maximum-text size. Solving this will require changing the configuration. Here a related SO QA - https://stackoverflow.com/questions/66825888/maximum-text-size-in-diagram-exceeded-mermaid-js.

I noticed that you are upgrading Mermaid-JS here - #5168
I was hoping maybe you could look into the above limitations as well.