Dual licencse under Apache 2.0 and MIT

[badcodecat]

Context: I am in the process of developing a plugin to add PXO file support to the Bevy game engine. Notably, Bevy plugins are typically dual-licensed under the Apache 2.0 and MIT licenses, like the main bevy project. This dual licensing approach has several advantages, as discussed in this Bevy issue.

It would be nice to be able to do the same for the PXO Plugin I'm working on.
Thanks for your consideration.

[appybara13]

Thanks @badcodecat for your contribution with #3, I'll make the request license change now and then publish.