Update bevy_rapier2d to 0.29 + bevy_rapier3d to 0.29

[AS1100K]

This PR updates the bevy example code for the latest version of bevy_rapier2d and bevy_rapier3d.

I think that we should also state which version this guide uses for bevy_rapier2d, bevy_rapier3d, and other rapier crates, this allows the user to not struggle when the documentation is not up-to-date with the latest version.

Also, in 0.29 two new things were added

• picking_backend
• geometry::to_bevy_mesh

I also, think that we should document at least picking_backend feature in the user guide.

TODO

• Upgrade bevy_rapier2d and bevy_rapier3d to 0.30, once it is released

[ThierryBerger]

• Thanks for the PR! update to bevy_rapier 0.30 + bevy 0.16 #139 is now more up to date so I'll close this.

I definitely agree that version information should be disclosed somewhere!