Bump to v1.21.0 stable (ScratchAddons#3645)

Bump to v1.20.2 stable (ScratchAddons#3544)

Bump to v1.20.1 stable (ScratchAddons#3533)

Bump to v1.20.0 stable (ScratchAddons#3506)

Bump to v1.19.1 (ScratchAddons#3369)

Bump to 1.19.0 stable (ScratchAddons#3354)

Bump to stable (ScratchAddons#3228)

* Bump to stable

* Update manifest.json

Merge pull request ScratchAddons#3111 from apple502j/v1.17.2

v1.17.2

Bump to v1.17.1 stable (ScratchAddons#3054)

Bump to 1.17.0 (ScratchAddons#3000)