Support for Marimo (Notebook alternative)

[almarklein]

See https://github.com/marimo-team/marimo

ref fastplotlib/fastplotlib#760

Would be nice if we can move some stuff out of a jupyter_rfb into a generic lib (across multiple browser-based tools, and across different render engines (wgpu/rendercanvas / vispy, datoviz, etc)

[arniwesth]

I second that. Marimo is an excellent alternative to Jupyter, and for more software-oriented teams, it should be the first choice due to its git friendliness and easier code reviews.

[tlambert03]

would be amazing :)