Add more details to the reference section about provision_data

[plars]

Description

• move the maas storage custom config documentation out to the main documentation directory
• reformat the maas storage custom config docs and link to TOC
• add per-device-connector documentation for all the support provision_data options we currently support

Resolved issues

Resolves one part of CERTTF-298

Documentation

yes

Tests

Built locally using make html from the docs directory

[tang-mm]

I appended some edits here directly to fix the doc checks, mainly changing the key names to use the code syntax so the spelling check will ignore them.

I also updated the tutorial to use the "simpler" maas provision_data fields and then point to the device_connector document (a1a92dd). Please check if it's appropriate

[plars]

Thanks, those look good to me, but I think we need another reviewer.

[andrejvelichkovski]

Looks good to me!