Add a VE menu option to facilitate the creation (and editing) of Maps in VE supported pages

[revansx]

Currently, the ability to embed Maps from the geojson namespace into VE pages in the main namespace requires manual editing of the main page source code. While effective for those users comfortable with advanced wiki markup, this is presumably a barrier to users who are only comfortable editing using VE.

This ticket is a request for there to be a VE menu option (similar to what Kartographer provides on wikimedia sites) that allow VE users to insert maps without seeing the wiki source directly.

Ref: https://www.mediawiki.org/wiki/Help:VisualEditor/Maps

P.S. - The Maps Extension is great! .. Thank you!!