wrong link in the doc

[JOduMonT]

https://docs.cloudron.io/apps/mastodon/#local_domain-is-an-app-on-cloudron
the link for well-known-uris is not working

it should point -> https://docs.cloudron.io/apps/#well-known-uris
instead of -> https://www.cloudron.io/apps/#well-known-uris

[girish]

Thanks! Fixed