update http://cds-hooks.org/community/ to remove Argonaut sprint details

[isaacvetter]

The CDS Hooks Program was successfully completed around the end of calendar year 2017.

We should remove this content from the community page:

CDS Hooks Sprint Program Objectives Promote creation of clinical-grade service integrations (EHRs + CDS Services) Gain implementation experience with real-world systems Refine the spec, balancing ease of use, flexibility, and stability Drive toward pilot deployments with the ability to measure results