It's been part of Edge for a long time. From any site click the triple dots on the top right of Edge; click on Apps about halfway down; click on "install this site as an app"; click on install.
A new windows app will be created based in the website. I use this a lot for sites I use regularly...even Stardock.
In the Windows 11 start menu it shows up in the App list immediately and can be pinned to Start menu like any other program.
It does eventually show up in the Start11 app list with a little coaxing and can be pinned to its start menu as I showed you but exhibits the problems that I started this thread with.