update custom metadata to explain 5 metadata limit (#18359)

* Update custom-metadata.mdx

* Update limits.mdx

* Update limits.mdx

Author: kathayl

src/content/docs/ai-gateway/configuration/custom-metadata.mdx

@@ -14,6 +14,13 @@ Custom metadata in AI Gateway allows you to tag requests with user IDs or other
 * **Enhanced Logging**: Metadata appears in your logs, allowing for detailed inspection and troubleshooting.
 * **Search and Filter**: Use metadata to efficiently search and filter through logged requests.
 
+:::note
+
+
+AI Gateway allows you to pass up to five custom metadata entries per request. If more than five entries are provided, only the first five will be saved; additional entries will be ignored. Ensure your custom metadata is limited to five entries to avoid unprocessed or lost data.
+
+:::
+
 ## Supported Metadata Types
 
 * String

src/content/docs/ai-gateway/reference/limits.mdx

@@ -11,15 +11,16 @@ The following limits apply to gateway configurations, logs, and related features
 
 | Feature                                                         | Limit                               |
 | --------------------------------------------------------------- | ----------------------------------- |
+| Cacheable request size                                          | 25 MB per request                   |
+| Custom metadata                                                 | 5 entries per request               |
 | Datasets                                                        | 10 per gateway                      |
 | Gateways                                                        | 10 per account                      |
+| Gateway name length                                             | 64 characters                       |
 | Logs stored [paid plan](/ai-gateway/reference/pricing/)         | 10 million per gateway <sup>1</sup> |
 | Logs stored [free plan](/ai-gateway/reference/pricing/)         | 100,000 per account <sup>2</sup>    |
 | Log size stored                                                 | 10 MB per log <sup>3</sup>          |
 | Logpush jobs                                                    | 4 per account                       |
 | Logpush size limit                                              | 1MB per log 	                      |
-| Gateway name length                                             | 64 characters                       |
-| Cacheable request size                                          | 25 MB per request                   |
 
 <sup>1</sup> If you have reached 10 million logs stored per gateway, new logs
 will stop being saved. To continue saving logs, you must delete older logs in