Update context to be inline with new sec:

[bahner]

I am just starting out writing an implemenation of did:ipid for elixir. It's complex, all right.

What I did notice reading the upstream specs is that publicKey is deprecated in favour of PublicKeyMultibase. That makes things a little easier for us IPFS folks. I suggest to change the context and bump the version number to 1.2.

I would like to partake in some of the chores here, if needed. I need a did, and did:ipid is probably the best for the job.

I can be contacted oob from my profile, if needed. I zoom and slack and teams and what not.