Adds rake task to generate json blob of function docs

[auzlee]

[chrismetcalf]

@avaleske You might want to check out https://dev.socrata.com/soql.json, which is already generated by Jekyll on every build.

[TranquilMarmot]

@chrismetcalf get outta here!

That looks close to what we need, but it's missing some of the fields i.e. we want to display title in a list of functions, but in the details for the function show the value for function

Looks like we might be able to just change soql.json to include title and get what we need. 🤔

[chrismetcalf]

😜 You’ll never be rid of me!