Add "mental healthcare" to terminology "setting" group

Yes agree on “mental healthcare”

I was also in doubt, but thought there should be consistent with the other setting name. But my own preference would be also 'mental healthcare'. @Joost Holslag agree? (I guess yes, since that was his first suggestion)

I would have thought this should be ‘mental healthcare’. If you type ‘mental care’ into google, everything comes back ‘mental healthcare’