Ability To Build/Bundle Multiple Platforms At Once

[DogeDark]

Feature Request

Add the ability to specify all or a list of platforms to create builds/bundles from. This would make releasing multi-platform projects as simple as a single command.

Implement Suggestion

We could make the --platform flag support --platform all or --platform web,desktop,fullstack.

It may also be nice to have a list of platforms in Dioxus.toml that a project supports which dx will build/bundle from instead of manually specifying --platform web,desktop,x,y,z