RenderOptions
By moving `RenderOptions` out of `Option`, because the two structs' uses are almost entirely separate. The only complication is that `unstable_features` is needed in both structs, but it's a tiny `Copy` type so its duplication seems fine.
close_tag()
.sub-logo-container
UrlPartsBuilder::push_fmt
crate
.line-number
.line-numbers
Symbol
String