Consider and integrate existing API resources

[gbinal]

• [x] https://pages.18f.gov/API-All-the-X/pages/agency_checklist/
• [ ] https://pages.18f.gov/API-All-the-X/pages/procurement_language/
• [x] https://pages.18f.gov/API-All-the-X/pages/policy_documents/
• [x] https://pages.18f.gov/API-All-the-X/pages/agency_api_strategy/
• [x] https://pages.18f.gov/API-All-the-X/pages/how_to_get_started_with_apis/
• [x] https://pages.18f.gov/API-All-the-X/pages/developer_engagement-a_model/
• [x] https://pages.18f.gov/API-All-the-X/pages/ensuring_discoverability-a_guide/
• [x] https://pages.18f.gov/API-All-the-X/pages/sample_api_requirements/

[gbinal]

The sample api requirements document is more up to date and useful than the procurement language document linked above.

[gbinal]

Done. The results have been added to the deliverables section