Improve IPNS docs

[lidel]

Right now, https://docs.ipfs.tech/concepts/ipns/ is more like a publishing tutorial/how-to, than an explainer of an abstract concept.

I propose:

• moving Example IPNS Setup with CLI section to a separate how-to in https://docs.ipfs.tech/how-to/publish-to-ipns-from-cli/
• reusing "The InterPlanetary Name System (IPNS)", "Deep Dive into IPNS", and "Pubsub + IPNS" sections from https://github.com/protocol/launchpad/pull/188 to create proper explainer at https://docs.ipfs.tech/concepts/ipns/
  • ...and then linkomg to the separate hands-on how-to at the end in a ::: callout block.

cc @2color @mrodriguez3313 @johnnymatthews

[2color]

Sounds like a good idea to me. Assigned to myself for now.

[TMoMoreau]

Looks like this is done now based on that PR being merged. Going to close this issue. :)