v0.3.0 for bevy 0.16

What's Changed

• make OpenXR event handlers completely safe! (no unsafe!) by @Schmarni-Dev in #183
• 0.16 support by @MalekiRe in #178
• XrSpaceSyncSet and OxrSessionConfig by @Schmarni-Dev in #184
• move hand debug gizmos into bevy_mod_xr by @Schmarni-Dev in #185
• chore: bump version number by @Schmarni-Dev in #186
• move bevy_xr_utils example i forgot to move by @Schmarni-Dev in #187

Full Changelog: v0.2.1...v0.3.0