Update Prototype Kit docs support page

[kellylee-gds]

No description provided.

[36degrees]

I've updated and force pushed a change to:

• use HTML links rather than markdown links (which don't work in this context)
• tweak the wording to align with what we're using elsewhere

[stevenjmesser]

It's possibly worth linking to or duplicating the content written elsewhere about the levels of maintenance and support we're able to offer given the constraints. 'Maintenance' or 'support' can sometimes be read as full-on feature development but the other docs are quite explicit at how deeply we're able to work on it given other commitments.

I'll approve this but the above is a suggestion you could take in before merging.

[36degrees]

I've force-pushed to remove 4e9450f as we need to use HTML links in the Prototype Kit docs