Definitions in headers cause linker issues with multiple compilation units

[vekkuli]

If you have multiple compilations units using the library, you get "multiple definitions" linker errors because of the functions defined in the header files, namely events.h. I guess a solution could be to inline those as well.

Off topic:
Great project! I'm glad I ran into this. I was looking for precedence to programming RP2040 async style. I hope the library catches on and keeps getting developed and maintained.

[FunMiles]

Sorry I've been away, still doing async coroutines though.
@vekkuli I presume you added a few inline and got it working. You can do a pull request if you want.