Multiplatform version

[rjaros]

Nice work!
At least a big part of this library could be made multiplatform. It would be awesome to have such multiplatform core library.

[LukasForst]

Hey, thank you!

The majority of the function were refactored out of the JVM projects and the rest was developed directly for katlib on JVM. I don't have any experience with multiplatform Kotlin (yet). However, it seems like a nice exercise to try to split it into core and jvm libraries so I'll look into it.