docs: Add callout on ip-ranges endpoint (#13856)

Author: chargome

docs/security-legal-pii/security/ip-ranges.mdx

@@ -11,6 +11,12 @@ apply to self-hosted or single tenant.
 
 </Alert>
 
+<Alert title="API Access" level="info">
+
+You can programmatically access this IP range information via our API at `docs.sentry.io/api/ip-ranges`.
+
+</Alert>
+
 ## Dashboard and API
 
 Sentry's dashboard and API are both served from different domains, depending