docs: update batch trigger concurrency limits (#3171)

Author: ericallam

docs/limits.mdx

@@ -131,9 +131,9 @@ When you send a batch trigger, we convert it into individual runs. This limit co
 
 | Pricing tier | Limit                 |
 | :----------- | :-------------------- |
-| Free         | 1 concurrent batch    |
+| Free         | 5 concurrent batches  |
 | Hobby        | 10 concurrent batches |
-| Pro          | 10 concurrent batches |
+| Pro          | 50 concurrent batches |
 
 ## Log retention