Degrees for adverbs

[balmas]

Vanessa Gorman has requested degrees be added for adverbs.

[balmas]

@gcelano says

Degree is added for Latin and Greek in:

https://github.com/latin-language-toolkit/arethusa-configs/blob/gcelano/configs/arethusa.morph/lat_attributes.json

https://github.com/latin-language-toolkit/arethusa-configs/blob/gcelano/configs/arethusa.morph/gr_attributes2.json