Update links for the faucet on docs and other areas

[34r7h]

https://faucet.testnet.lukso.network/

And make it clear it won't work on L16

[Hugoo]

Hey hi, the link is already here:

https://docs.lukso.tech/networks/testnet/parameters

It is on TESTNET page (not L16) so it is good.

Is there anything else you want to flag? I will close for now. Please feel free to answer and re open if needed.

Thanks