routes/github-login: Add documentation
routes/github-login: Add documentation

achanda/crates.io,Susurrus/crates.io,steveklabnik/crates.io,rust-lang/crates.io,Susurrus/crates.io,achanda/crates.io,rust-lang/crates.io,achanda/crates.io,rust-lang/crates.io,steveklabnik/crates.io,steveklabnik/crates.io,rust-lang/crates.io,achanda/crates.io,Susurrus/crates.io,steveklabnik/crates.io,Susurrus/crates.io