Let's Parkour

Changed the mod's Java package to com.serilum.*.
Updated mod information in the mods.toml and fabric.mod.json files.
No functional changes.

The complete changelog with detailed information about previous versions can be found on my website:
 > https://serilum.com/mods?changelog=lets-parkour

To the following people for supporting this mod's development! Downloading is already more than enough. But if you would like to contribute too and have your name here, check out serilum.com/donate.