Radical

Implement JSON-LD writing for Jena :
    a no-brainer

￼Added some documentation for Generic Parameters, with @tparam :
    it is actually pasted in 3 files; maybe do that only in RDFStore.scala ?
Sorry for extra path org.w3.banana.io.
I generally write myself a space after the commas,
but my understanding is that the pre-commit script does correct this,
and does not let one commit without correction.

It's not clear why it did not work this time.