Update limits.mdx

added that workers paid only

Author: kathayl

src/content/docs/browser-rendering/platform/limits.mdx

@@ -5,6 +5,10 @@ sidebar:
   order: 30
 ---
 
+</Description>
+
+<Plan type="workers-paid" />
+
 import { Render } from "~/components"
 
 | Feature                                       | Limit                                                         |