Support mutli-document YAML files

[Wikiwix]

For YAMLs it would be great to be able to compare mutli-document files.

For JSON potentially ndjson could be supported, too.

[josephburnett]

This is an interesting idea. How do you imagine this would look like on the commandline? And how would it treat the order of the documents with the A and B inputs?

I suppose we could just read a multi-document file (YAML or JSON) and push that into a jsonArray time. Then we can let the user supply keys to match up documents (existing feature).

[Wikiwix]

Sounds good to me, the list should per default handled as multiset (-mset) though, because the YAML documents do not have an order, but "repetitions" matter