docs(api-server): add rate limit data API window configuration

- Add description for `RATE_LIMIT_DATA_API_WINDOW_MINUTES` configuration variable
- Include default value and unit (hours) for the time window

Author: fulleni

src/content/docs/api-server/guides/configure-environment-variables.mdx

@@ -147,3 +147,5 @@ The number of general data API requests a user can make within the defined windo
 -   **Default:** `1000`
 
 #### `RATE_LIMIT_DATA_API_WINDOW_MINUTES`
+The time window, in hours, for the data API request limit.
+-   **Default:** `1`