Add additional breakpoint for parameter form; force param name to wrap
where necessary; remove top margin on tab bar.
Remove legacy browser support from clearfix mixin to get rid of console
warnings.
Allow for absent endpoint description.
Add required attibute to inputs of required fields; disable auto
complete on numerical inputs; add labelling.
Allow users to navigate tabs.
Restore submit functionality; switch tab automatically when user submits
a request.
Add clearable input functionality.
Make submit button fixed positioned under certain conditions; improve
usability of tabs.

Conditions are: the endpoint’s form exceeds the viewport, the viewport
is taller than 545px, the viewport is wider than 1000px, and the browser
supports CSS calc (and has JS enabled so that this can be detected). If
any of these conditions are not met, the button will remain in its
original position.
Remove autofocus on endpoint form.

Autofocus should only be used when there is near absolute certainty that
the user will take a certain action, and even then only sparingly. In
this case, the user may not necessarily wish to use the form, she could
merely be seeking information from it. Even if she does use the form
she may not always wish to give a value to first field. It’s better not
to second guess the user in this case.