add note about max_instances not being enforced locally

Author: dario-piotrowicz

src/content/docs/workers/wrangler/configuration.mdx

@@ -1098,6 +1098,9 @@ The following options are available:
     request to run a container than this number, the container request will error. You may have more Durable Objects
     than this number over a longer time period, but you may not have more concurrently.
 
+  - This value is only enforced when running in production on Cloudflare's network. During local development
+    the limit is not applied, so you may run more instances than specified.
+
 - `name` <Type text="string" /> <MetaInfo text="optional" />
 
   - The name of your container. Used as an identifier. This will default to a combination of your Worker name, the class