Update limits.mdx (cloudflare#23128)

Author: pulkitacloudflare

src/content/docs/analytics/analytics-engine/limits.mdx

@@ -12,7 +12,7 @@ head:
 The following limits apply to Workers Analytics Engine:
 
 * Analytics Engine will accept up to twenty blobs, twenty doubles, and one index per call to `writeDataPoint`.
-* The total size of all blobs in a request must not exceed 5120 bytes.
+* The total size of all blobs in a request must not exceed 16 KB.
 * Each index must not be more than 96 bytes.
 * You can write a maximum of 25 data points per Worker invocation (client HTTP request). Each call to `writeDataPoint` counts towards this limit.