Doc build still broken

[Ms2ger]

Even with servo/webrender@c23d3cf, we get

 Documenting webrender v0.1.0 (https://github.com/servo/webrender#c23d3cfe)
   Compiling webrender v0.1.0 (https://github.com/servo/webrender#c23d3cfe)
<stdin>:1:1: 1:2 error: unknown start of token: \u{256d}
<stdin>:1 ╭─
          ^
thread '<unnamed>' panicked at 'Box<Any>', ../src/libsyntax/parse/lexer/mod.rs:1437
note: Run with `RUST_BACKTRACE=1` for a backtrace.
Build failed, waiting for other jobs to finish...
Could not document `webrender`.

[frewsxcv]

This was fixed by servo/webrender#204.