api.rocket.rs

Builds the docs for api.rocket.rs.

How it works (`build.sh`)

When a commit gets pushed to any branch in Rocket, a webhook fires, triggering ./build.sh that:

Clones Rocket to _rocket.
Creates a worktree for each branch _build.
Builds the docs in parallel in each worktree, if cache is stale.
Copies each $worktree/target/doc to _output/$branch.
Copies static/* to _output/.
Uploads _output to api.rocket.rs.