Add link to "Useful functions" in macro docs (#7446)
* Add link to "Useful functions" in macro docs
Help people find additional features they can activate within a macro
* Update docs/feature_macros.md
Co-Authored-By: Drashna Jaelre <drashna@live.com>
Co-authored-by: skullydazed <skullydazed@users.noreply.github.com>
Co-authored-by: Drashna Jaelre <drashna@live.com>