Gallery format

A single directory for each "project".

A index.md file in the directory explaining what it is. (Link this into the main mkdocs.yml file in the gallery section).

A header, explaining what it is and what it is made of. Use an <img> tag with align="right" to show

Some pictures. Use <img> tags.

An .stl file is optional.

Other source files (e.g. OpenSCAD, Fusion 360, ...) are optional.

TODO: STL visualizaton; figure out an automatic build of all projects with latest plycutter plus visualization of the resulting sheet model.