Finatra: docs for new thrift APIs
Finatra: docs for new thrift APIs

Problem/Solution
Finatra has new thrift APIs, but documentation has not yet been updated to
reflect it. This updates examples and docs.

JIRA Issues: CSL-7122, CSL-7191, CSL-7193

TBR=true

Differential Revision: https://phabricator.twitter.biz/D255026

twitter/finatra,twitter/finatra,twitter/finatra