Auto merge of #3977 - rap2hpoutre:patch-1, r=alexcrichton
Auto merge of #3977 - rap2hpoutre:patch-1, r=alexcrichton

Added a base font size

See https://github.com/rust-lang/crates.io/pull/689 (ping @carols10cents)

A base font size was added to crates.io, here is the same addition for docs.crate.io

durka/cargo,tsurai/cargo,vojtechkral/cargo,nipunn1313/cargo,rustyhorde/cargo,tsurai/cargo,tsurai/cargo,achanda/cargo,vojtechkral/cargo,tshepang/cargo,rust-lang/cargo,rustyhorde/cargo,durka/cargo,rust-lang/cargo,eminence/cargo,rust-lang/cargo,tshepang/cargo,tshepang/cargo,tsurai/cargo,nipunn1313/cargo,nipunn1313/cargo,durka/cargo,durka/cargo,vojtechkral/cargo,rust-lang/cargo,achanda/cargo,vojtechkral/cargo,tsurai/cargo,rustyhorde/cargo,eminence/cargo,eminence/cargo,nipunn1313/cargo,eminence/cargo,achanda/cargo,achanda/cargo,rustyhorde/cargo,tshepang/cargo