Guide: Working with verifiable credentials in NodeJS

[rkreutzer]

Additional setup steps for using VCs

[jasheal]

@rkreutzer Thanks for the contribution!

We are planning on creating a more extensive section dedicated to working with verifiable credentials but if you (or anyone else) would like to take a stab at it, here's what I'm thinking the flow should be like ~

• Intro paragraph about working with credentials clarifying that identities are used to sign the data. Link to relevant sections of the docs.
• Add the required plugins to your agent
• Issue a self signed credential
• Issue a credentials to another identity
• Querying and filter for those credentials by issuer, subject, claim etc

[jasheal]

Let's hold off until full guide is complete

[mirceanis]

looks good to me