MicroSim Index Grid Format

Prompt

Modify the @docs/sims/index.md file to use the mkdocs-material grid
format. Use this example:

https://github.com/dmccreary/intro-to-physics-course/blob/main/docs/sims/index.md for the format

of the structure for each MicroSim.

Generate a screen shot using the @~/.local/bin/bk-capture-screenshot program if there is no .png file within the microsim directory.
You must pass the path to the microsim to this shell script.