Don't use username Github in subgraph link

[MixasV]

We know that the link to each subgraph in addition to the address to the site is built according to the principle .../username/subgraph-name .But if the user for some reason decides to change his name at the GitHub, then in the link to his subgraph changes. This leads to the fact that then there is no way to get access to information from the subgraph.