Update "about" in repository homepage sidebar #575
Description
The html-aam repository's About (in the sidebar) reads:
HTML Accessibility API Mappings - new spec updates should be made in https://github.com/w3c/aria/tree/main/html-aam
This should probably be updated some way, e.g., changing the link to point to the main ARIA repository or just removing the second part (to match all other repositories).