Inability to specify package output directory in reflex init

[rjulian]

While you can specify an output directory for reflex package, you cannot for reflex init and therefore the package location is fixed at package_build.

I'm in favor of either using a static directory name (sticking with package_build) or adding the option (with sane default) to all relevant CLI commands (init, build, package). I see little reason end users would need to make their own directory name.