Add command get-entity

[nichtich]

To emit the JSON format of edit/create-entity. I think this is the same as

data --simplify --keep ids,references,qualifiers,nontruthy

[nichtich]

The question has been raised in #68 but the answer to just use --simplify does not work because it eleminates qualifiers and references. The default should be round-tripping save to create-entity

[maxlath]

what would you think of a skeleton command, tailored to work with both wd edit-item and wd create-item:

• without an id, simply outputs an empty entity skeleton to prepare wd create-item (possibly with tips if we use a format that allows comments Support HJSON as input format #71)
• if passed an id, wd skeleton $id <=> wd data --simplify --keep all (with indented data output to ease edition)

[nichtich]

Yes, that would be less confusable with command data. Options that make sense:

-p, --props <props>  as in wd-data
-l, --lang <langs> limit data so selected language(s)
-f, --format <format>  Default: json. Alternatives: js

[maxlath]

I just published v7.3.0, which includes a new command based on this idea: [wd generate-template]
(https://github.com/maxlath/wikidata-cli/blob/master/docs/read_operations.md#wd-generate-template).

Instead of --lang, I went for a more precise version of props:

wd generate-template Q123 --props labels.de,sitelinks.dewiki

As for the JS format, the implementation is somewhat hacky, but it seems to work from what I could see, could you give it a try?

wd generate-template Q123 --format js