Local build fails for `derivative` and `syn` docs.

[connortsui20]

In Poker Lab, there is a dependency on the derivative crate, which also takes a dependency on syn.

For some reason, when adding the generated docs for Poker Lab, the local build (npm install && npm run-script start) fails / errors out on those two crates' documentation.

The solution I have for now is just running cargo doc --no-deps and using those docs instead (which is more than sufficient), but I'm going to make this issue so that it's recorded somewhere.

[connortsui20]

Just ran into this problem again with the either crate. Using cargo doc --no-deps for row lab as well.