allow to add extensions via mw api query

[WolfgangFahl]

e.g. https://www.mediawiki.org/wiki/Category:Extensions_included_in_Canasta as input should produce a json file with extensions form that category.

[tholzheim]

#MediaWiki Extension
SELECT ?item ?itemLabel ?inception ?name ?publicationDate ?sourceCodeUrl ?version
WHERE 
{
  ?item wdt:P31 wd:Q6805426.

  OPTIONAL{?item wdt:P1448 ?name.}
  OPTIONAL{?item wdt:P571 ?inception}
  OPTIONAL{?item wdt:P577 ?publicationDate}
  OPTIONAL{?item wdt:P1324 ?sourceCodeUrl}
  #OPTIONAL{?item wdt:P348 ?version}
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". } 
}

Try it!

[WolfgangFahl]

https://www.mediawiki.org/wiki/Module:ExtensionJson