decoNote: constraints or type attribute value recommendations

Do we want to add any tests/constraints on decoNote.

At present, the type attribute offers some recommended values, but will accept others. Do the following values work for everyone? Are any more required:

bas-de-page
border
cadel
canonTable
carpetPage
chrysography
colInit
decInit
diagram
flourInit
headpiece
headpiece
histInit
illustration
initial
instructions
lineFill
map
marginal
micrography
miniature
none
other
plainInit
rubrication
unfilled

tei-for-special-collections / consolidated-schema

decoNote: constraints or type attribute value recommendations #3