Nicely done, clear and helpful. These might be relevant improvements:

• In section 2 ("Localize your own groups") there seems to be a reference annotation after MediaWiki:Wikibase-sitelinks-yourgroupnamehere. It seems not to be linked to anything.
• In section 4.1 it might be good to add a hint for the relevant field in case it's not clear from the labels, something like: "in your wiki and try to link an existing page (field Site ID) on one of the above configured sites to an existing Item (field ID). "

To avoid wikidata-query-rdf build CI running query-gui browser tests we have moved the wdio tests into a separate task: grunt browser_test.
This will be called in npm deploywhich in its turn gets run as part of wikidata-query-gui-build. This resolves the issue discussed in this task.

Please review the extension documentation page https://www.mediawiki.org/wiki/Extension:WikibaseSchema
@Michael @Lucas_Werkmeister_WMDE @hoo

This is waiting for language parameters in edit summaries to be fully implemented

This means adding a 'getNameBadgeById()' to the SchemaDispatcher and using it in Special:SetSchemaLabelDescriptionAliases instead of getMonolingualSchemaData()

Most of this is resolved or handled in other tickets, closing

SpecialPage should include Copyright Info (like the Schma page currently does)