update holochain DHT description of metadata

[zippy]

Currently under the holochain DHT section the language around meta-data attached doesn't reflect changes to our new linking language. We should update it using some of the language from:
https://hackmd.io/IYIwjADCBsBMDGBaYYAmFEBZUDNrOAgFNExoBWAZkr0yIA5hUg==

[JeanMRussell]

Great. Has this been done? If not, who is it assigned to? what is next action?

[zippy]

I think part of the next actions are to set up realms of accountability and see who wants to take this on, then when we find things like I did here, that person would take it on. At the time I added this ticket there was a very active dev_docs doop that was meeting twice a week, mostly Art and Matthew so I assumed they would move this ball forward, but they now have different focus.