docs: add Xquik OpenAPI source example

Author: kriptoburak

README.md

@@ -112,6 +112,20 @@ executor call executor openapi addSource '{
 }'
 ```
 
+For an X data workflow, Xquik's public OpenAPI spec works the same way:
+
+```bash
+executor call executor openapi addSource '{
+  "spec": "https://xquik.com/openapi.json",
+  "namespace": "xquik",
+  "baseUrl": "https://xquik.com/api/v1"
+}'
+```
+
+Create a connection for the source in Executor and store the required `x-api-key`
+credential there, so agents can search X data and run Xquik tools through the
+shared catalog without copying credentials into each MCP client.
+
 Use `baseUrl` when the OpenAPI document has relative `servers` entries (for
 example `"/api/v3"`). Confirm it is live with `executor tools sources`.