Store packages and their website in a YAML instead of a _redirects file

[cderv]

This could be easier to maintain - this would require to be able to read this YAML and write the correct _redirects file at each build.

Does it worth the change over adding a new line in _redirects ?

Sharing the idea here as we discussed it with @apreshill

[apreshill]

Yes I think that is a great idea- we really only need the package name and the Netlify provided subdomain for the rewrite to work.

[cderv]

This will also be necessary to better handle new website in PR, specifically when the redirect does not work yet and hex logo can't be retrieved. See #8