Clarify negative patterns when limited

Author: korinne

src/content/docs/workers/static-assets/billing-and-limitations.mdx

@@ -13,7 +13,7 @@ Requests to a project with static assets can either return static assets or invo
 
 - Requests to static assets are free and unlimited. Requests to the Worker script (for example, in the case of SSR content) are billed according to Workers pricing. Refer to [pricing](/workers/platform/pricing/#example-2) for an example.
 - There is no additional cost for storing Assets.
-- **Important note for free tier users**: When using [`run_worker_first`](/workers/static-assets/binding/#run_worker_first), requests matching the specified patterns will always invoke your Worker script. If you exceed your free tier request limits, these requests will receive a 429 (Too Many Requests) response instead of falling back to static asset serving.
+- **Important note for free tier users**: When using [`run_worker_first`](/workers/static-assets/binding/#run_worker_first), requests matching the specified patterns will always invoke your Worker script. If you exceed your free tier request limits, these requests will receive a 429 (Too Many Requests) response instead of falling back to static asset serving. Negative patterns (patterns beginning with `!/`) will continue to serve assets correctly, as requests are directed to assets, without invoking your Worker script.
 
 ## Limitations