Fix link to new documentation

What does this Merge Request do?

Follows !1344 (merged), fixing a broken link I noticed immediately after merge.

While here, adopted more active language for the headings.

CC @tauriedavis

Merge Request checklist

• Tests added for new functionality. If not, please raise Issue to follow-up.
• This change is backward compatible. If not, please include steps to communicate to our users.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.