Update limits.mdx

info on future pricing/billing

Author: kathayl

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

@@ -38,6 +38,7 @@ import { Render, Plan } from "~/components";
 
 While the limits above define the maximum number of concurrent browser sessions per account, in practice you may not need to hit these limits. Browser sessions close automatically—by default, after 60 seconds of inactivity or upon task completion—so if each session finishes its work before a new request comes in, the effective concurrency is lower. This means that most workflows do not require very high concurrent browser limits.
 
+## Pricing
 
-
+Browser Rendering service is currently available at no cost. You can use the service within the limits specified above without incurring charges **until billing begins**. We will provide advance notice before any billing begins.