A faster, easier way to give context about HMDA

[dezzie]

We received feedback that developers did not feel they had enough context around HMDA data. The places where we tried to provide that context were ineffective because:

• the language had "too much politics and not enough about the information"
• the language read like a history lesson
• links to learning more led to esoteric documents
• our link to the "What is HMDA?" video was placed in the Field Reference page, which had its own problems. No one watched it.

Most devs are also not coming to the docs from the HMDA site, so embedding the video isn't a redundant use of content.

Proposed fix:

• [ ] Let's give our HMDA video another chance. It did, after all, win a plain-language award, and we thought it was the best way to introduce people on the HMDA website too.