[SYCL][Graph] Adding new graph enqueue function to spec

Author: reble

sycl/doc/extensions/experimental/sycl_ext_oneapi_enqueue_functions.asciidoc

@@ -709,6 +709,31 @@ optimize such partial barriers.
 _{endnote}_]
 |====
 
+==== Command Graph
+
+The functions in this section are only available if the
+link:./sycl_ext_oneapi_graph.asciidoc[
+  sycl_ext_oneapi_graph] extension is supported.
+
+|====
+a|
+[frame=all,grid=none]
+!====
+a!
+[source,c++]
+----
+namespace sycl::ext::oneapi::experimental {
+
+void submit(sycl::queue q, command_graph<graph_state::executable> g);
+
+}
+----
+!====
+_Constraints_: Device and context associated with queue need to be identical 
+to device and context provided at command graph creation.
+
+_Effects_: Submits an executable command graph to the `sycl::queue`.
+|====
 
 == Issues