Improve description in specification of AUDIT_DETAILS.change_type and description fields

@Thomas, in https://openehr.atlassian.net/browse/SPECPR-260 the proposed additions to audit change type terminology where "addition" and "removal" that would be applied for FOLDER.items changes.

Current terminology doesn't seem to include the proposed codes: https://github.com/openEHR/terminology/blob/master/openEHR_RM/en/openehr_terminology.xml#L26-L34

Where those codes added elsewhere?

Maybe I'm not looking at the right terminology trunk.

thanks - made the change to fix the wrong 666 code.

It seems to me that if you document addition or change of items referred to from FOLDERs, you can just document those change types (addition etc), and if it is on the directory (the EHR FOLDER structure) it is clear that the change is talking about FOLDERs. If you think we need more please say so.

@Thomas for https://openehr.atlassian.net/browse/SPECPR-260 I can't find the resolution about the FOLDER specific change types, is there any feedback about that?

Good point - a request to change the rubric can be raised as it says here at the bottom: https://www.openehr.org/releases/TERM/latest/docs/index