Description of the registration flow of the generated public key

[ritou]

In the current documentation(v0.1) I can't find any mention of how to get the DID by registering the SIOP generated public key.

RP can do that in advance, but SIOP requires the registration process to be done at the same time as the key pair is generated.
There may also be a delay before the DID document becomes available for reference. This explanation may be useful to developers.