DOCS-981 - Notification about TAXII 2

[jpipkin1]

Purpose of this pull request

This pull request adds this non-indexed notification: https://help.sumologic.com/docs/security/threat-intelligence/notice-about-taxii-2

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)

DOCS-981

[jpipkin1]

Thanks for the review, @kimsauce! I'm merging it now. I can make your updates to the article after it's published.

[jpipkin1]

And I can't make changes to wording since it's been approved by Legal.