Package index lacks Sublime Text compatibility annotations

[ToxicFrog]

Recent versions of RainbowBrackets don't work in ST3, since they rely on Python 3.8 features and new ST4 APIs. However, they aren't marked as being compatible only with ST 4.x in the package control index, so pcon will attempt to update to 4.2.0 even if you're running ST3, breaking the plugin.

You can still manually downgrade, but it would be better to properly annotate each release with the ST versions it supports so that pcon's auto-update doesn't install incompatible versions.

[superkeyor]

Yes. Please fix that. I am also stuck with ST3 right now and just found that the current version of RainboBrackets is not compatible with ST3. Thank you!