Recent docs build renders the left column oddly

[Lokathor]

https://docs.rs/imagine/0.0.6/imagine/

The gray background of the left column doesn't go all the way to the edge of the window.

[cynecx]

Probably caused by rust-lang/rust#91356.

cc @GuillaumeGomez

[GuillaumeGomez]

I have a fix for it in #1579.