Adding docs on different versions of lightning-kmp

[thunderbiscuit]

Hi there. Thanks for the fantastic work on this library!

I'm opening this issue because I've been hacking on the Cashu protocol a little bit and added this library as a dependency but was running into problems parsing my payment requests using the PaymentRequest.read(pr) API.

It turns out I had added the wrong dependency without realizing it; because my project is JVM-only I was using the

fr.acinq.lightning:lightning-kmp-jvm:1.5.12

library, and kept getting a java.lang.NoSuchFieldError: hash error when attempting to parse the payment request string. Changing my dependency to fr.acinq.lightning:lightning-kmp:1.5.12 fixed my issue, but it took me a bit of time to figure out that this was the thing to do because I initially misunderstood the error, and the readme doesn't have documentation on the use of the different versions of lightning-kmp (the installation section only points to info on how to build locally).

I think a small section on the readme on how to install from Maven Central and which libraries to use for which use case would be great! I'm also happy to contribute this if you'd like. Cheers!