Recommended RDNN differs from Flatpak Guidance

[jhaygood86]

According to https://docs.flatpak.org/en/latest/conventions.html, you should use "io.github.[username].[app]" not "com.github.[username].[app]"

[btkostner]

@cassidyjames This seems to be documentation changes. Right now there is no automated way to migrate. We can deprecate the old and release new if we wanted to. Or we can just recommend this for newly submitted apps. There is no current restriction in our current release process.

[danirabbit]

Closing since this seems to be documentation related and these days our docs do use io.github