Add missing parameters in srv.send

Author: mariayord

node.js/core-services.md

@@ -772,7 +772,7 @@ Error handlers are invoked whenever an error occurs during event processing of *
 
 ```ts
 async function srv.send (
-  method   : string | { method, path?, data?, headers? },
+  method   : string | { method, path?, data?, headers? } | { query, headers? },
   path?    : string,
   data?    : object | any,
   headers? : object
@@ -812,6 +812,10 @@ let req = new cds.Request (
 )
 return this.dispatch(req)
 ```
+Use this method instead of [`srv.run(query)`](#srv-run-query), if headers should be added to the request object. For example:
+```js
+await srv.send({ query: SELECT.from('Books'), headers: { some: 'header' } })
+```
 
 *See also [REST-Style Convenience API](#rest-style-api) below* {.learn-more}