feature (template): Collection column in Concepts tab

[markdoerr]

Collections are a nice way to loosely structure concepts in SKOS (one concept can belong to several Collections)
In the current template version, one needs to enumerate every concept in a comma separated list of Member IRIs in the Collection tab. This is very tedious and cumbersome.
A simpler approach would be to add a "Collections" column in the Concepts table. In that case, common spreadsheets suggest previously entered collection names as auto-completions, which simplifies input and reduces errors by typos.

[dalito]

@markdoerr Please have a look at #124 which has a draft for a new Excel table structure. If I understand you correctly it matches what you propose here.

[markdoerr]

Thanks for the hint, @dalito,
yes indeed, #124 is a good collection of improvements - I also agree with the order of priority :)
Looking forward to test the new table structure, once it is implemented.