Add sentence to enforcement page

[dorothyyeager]

Summary

What we're after:
As a person who is involved in a compliance matter, I would like to know when those documents are made public by the FEC.

OGC enforcement has requested that we link the policy on when documents are made live on the Enforcement page. (It lives on Policy and other guidance page because it's a policy.)

Completion criteria

• Sentence supplied by OGC enforcement and link to the related policy are added to the page's introduction.

By law, all enforcement cases must remain confidential until they’re closed. Closed enforcement cases can be accessed on this page and information about what documents are placed on the public record when cases are closed is available here [link to 2016 disclosure policy at https://www.fec.gov/resources/cms-content/documents/notice2016-06.pdf]

[dorothyyeager]

The new sentence has been added as requested to https://www.fec.gov/legal-resources/enforcement/.