some more best practices

See merge request !63

very slight updates to the design

See merge request !67

(as per yesterday's hub meeting, where the observation came up that
almost no one had yet really noticed that the howto contained anything
else / was updated since last year. Since we don't have a design yet,
this just slightly tweaks the colours to some that occurred in the
announcement blog post)

More details on adding a WA map to an assembly.

See merge request !64

Update map-best-practices.md

See merge request !65

Complete sentence

See merge request !66

# Conflicts:
#   docs/maps.en.md

Add missing doc on layer properties; small fixes

See merge request !62

attempt to fix theme

See merge request !61

Update maps.md --> `"copyright"` Property fixed, minor spelling

See merge request !60

# Conflicts:
#   docs/maps.md

Fix some typos in maps.md

See merge request !59

(currently, <code>-tags are weirdly white)

(also fix an error; tileset copyright goes into `tilesetCopyright`, not
`copyright`)

map & workadventure updates

See merge request !58

Workadventure

See merge request !57