DOCS-25 - Fix minor threat intel doc issues

[jpipkin1]

Purpose of this pull request

This pull request makes minor fixes to threat intelligence documentation.

It also removes a bit of announcement bar coding from docusaurus.config.js that was added by mistake with PR #3817 (see here). (That code was originally removed by PR #4371, but persisted in the threat intel PR.)

Select the type of change

• Minor Changes - Typos, formatting, slight revisions
• Update Content - Revisions, updating sections
• New Content - New features, sections, pages, tutorials
• Site and Tools - .clabot, version updates, maintenance, dependencies, new packages for the site (Docusaurus, Gatsby, React, etc.)

Ticket (if applicable)

For DOCS-25.