Upgrade to Bevy 0.16

[rparrett]

There probably won't be a crates.io release until Bevy 0.16.0 is properly released, but you can use this git branch in the mean time.

[dependencies.bevy_simple_text_input]
git = "https://github.com/rparrett/bevy_pipelines_ready.git"
branch = "bevy-0.16"