Add photo frame generator

Refactor to Dimensions dataclass, add golden ratio matting

Add label parameter to roundedPlate

Tidy stuff up, redo docs

De-indent

PhotoFrame: Add sample pictures

Add PhotoFrame.svg

Calculate frame based around pre-cut glass

Add mounting hole(s) to back of frame

Update web front-end to make mutually-exclusive configurations less confusing

Simplify user-visible options

Set default dimensions back to standard photo, regenerate example

Set default dimensions back to standard photo, regenerate example

Update help text for x and y, update sample image

Update defaults for mount hardware