Update link to release notes

[kprosise]

Rather than individual links, we are now linking to the folder on GitHub holding the notes.

QA: Built site and checked link, no issues found.

Quick fix, no related tracking issue to mention.

PR Template and Checklist

Please complete as much as possible to speed up the reviewing process.

Readiness and adding reviewers as appropriate is required.

All PRs should be reviewed by a technical writer/documentation team and a peer.
If effecting customers—which is a majority of content changes—a member of Customer Success must also review.

Readiness

• Merge (pending reviews)

Checklist

• Run spelling and grammar check, preferably with linter.
• Avoid changing any header associated with a link/reference.
• Run make linkcheck.
• View HTML in a browser to check rendering.
• follow best practices for commits.
  • Descriptive title written in the imperative.
  • Include brief overview of QA steps taken.
  • Mention any related issues numbers.
  • End message with sign off/DCO line (-s, --signoff).
  • Sign commit with your gpg key (-S, --gpg-sign).
  • Squash commits if needed.
• Request PR review by a technical writer and at least one peer.

[mike-scott]

LGTM