Automate handling of Developmental Spaces Manifesto endorsements

[rufuspollock]

atm this is via a google form and we have to add these by hand.

Notes:

• We'd like this to be automated
• And we have to beware of spam ...
• I think we could err on side of automation for now and worry about spam when it happens (not that likely atm) and we could hope that spam capture in the form submission handles this