Add numpad for number & range inputs

Implement tel input type

Add file-input support, upload missing files.

Add (partial) support image buttons.

Reorganize keyboard templates.

Implement typing, deletion.

Render onscreen keyboards (not interactive yet).

Render <select> elements to multi-column menus.

Implement radio inputs, upload missing files, make space for descriptions & richer form controls to use.

Add support for checkboxes, along with supporting infrastructure.

Add infrastructure for rendering Ginger templates.

Assemble testscript as locally-run webserver, adjust namespace.