generalized format for package updates [Enhancement]

[therealadityashankar]

I guess one of the core concepts of deno is being decentralized, and being restricted to

https://deno.land/std
https://deno.land/x
https://denopkg.com
https://dev.jspm.io
https://cdn.pika.dev
https://unpkg.com

Isn't good, cause people might want to use other domains - or perhaps their own domain, so like what could help would be a generalized update check format, i.e. if something like,

https://deno.land/std@versions could return all the versions in a json format, i.e.

returning something like

{
    "versions": ["0.0.1", "1.0.0", "1.0.1", "1.1.0", "2.0", "2.6.9"],
    "deprecated": ["1.*"],
    "fatal-risk-of-use": ["<1.0.0"],
    "dog-person-wrote-code": false,
    "cat-person-wrote-code": true
}