Description

Updates the enter() callbacks section of @lit-labs/router's README to match the implementation in routes.ts.

The current docs describe enter() as being able to "optionally reject that route as a match," and the dynamic-routes example comments that return false causes the next route to be matched. The implementation does neither: it only checks for strict-equal false, and on false it bails out of goto() silently without falling through to other routes.

Changes

• Add the enter type signature and parameter shape.
• Document the strict-false cancellation contract.
• Document that cancellation is silent — the goto() Promise still resolves, no event is fired, no error is thrown.
• Document error propagation: a thrown or rejected enter() surfaces through goto() with no internal handling.
• Reword the dynamic-routes example comment so it accurately describes why goto() is called before return false (it's how the new route gets matched, not a side-effect of returning false).
• Fix the example's render callback to interpolate params[0] (was rendering as literal text in the original).

Out of scope

The PathRouteConfig and URLPatternRouteConfig interfaces shown in the README are also out of date relative to routes.d.ts (they don't include enter, and they type params as {[key: string]: string} instead of {[key: string]: string | undefined}). Happy to follow up with a separate PR if useful.

Verification

Behavior described matches packages/labs/router/src/routes.ts goto() and BaseRouteConfig in routes.d.ts. No code changes.

Fixes #5328