Small incoherence in forms Thing Description core vocabulary

[relu91]

After #1191 landed we can now express "aggregate" operations also for events. However, in forms field description we say:

In this version of TD, all operations that can be described at the Thing level are concerning how to interact with the Thing's Properties collectively at once.

I think is sufficient to remove that sentence.

See here.

[egekorkan]

I think changing it to something like this would be better:

Forms in the Thing level are used for describing endpoints for a group of interaction affordances.

[sebastiankb]

from today's TD call: group agrees to replace the sentence with Ege's proposal

[sebastiankb]

issue solved