Show how to call Conduit API methods from clients

Summary: Fixes T3628. Ref T5955.

Test Plan:
On the method page, you see a generic example:

After making a call, you see a specific example with your parameters:

Reviewers: chad, btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T3628, T5955

Differential Revision: https://secure.phabricator.com/D12770