Support "try it out" requests to the server

[dgileadi]

A company project needed support for "try it out" functionality, where you can enter values into form fields, press a button to send the request to the server and display the response. The changes have now been open-sourced, and here they are.

This functionality doesn't appear by default, but can be enabled with the forms option.

[coveralls]

Coverage increased (+3.3%) to 61.55% when pulling 610d68b on dgileadi:olio-theme into c52a482 on danielgtaylor:olio-theme.

[coveralls]

Coverage increased (+3.3%) to 61.55% when pulling 610d68b on dgileadi:olio-theme into c52a482 on danielgtaylor:olio-theme.

[coveralls]

Coverage increased (+3.3%) to 61.55% when pulling 610d68b on dgileadi:olio-theme into c52a482 on danielgtaylor:olio-theme.

[coveralls]

Coverage increased (+3.3%) to 61.55% when pulling 610d68b on dgileadi:olio-theme into c52a482 on danielgtaylor:olio-theme.

[sashahilton00]

@danielgtaylor is there any news on this PR? Would be a great feature to have