[SPARK-13214][DOCS] update dynamicAllocation documentation

Author: Bill Chambers <bill@databricks.com>

Closes #11094 from anabranch/dynamic-docs.

docs/configuration.md

@@ -1169,8 +1169,8 @@ Apart from these, the following properties are also available, and may be useful
   <td>false</td>
   <td>
     Whether to use dynamic resource allocation, which scales the number of executors registered
-    with this application up and down based on the workload. Note that this is currently only
-    available on YARN mode. For more detail, see the description
+    with this application up and down based on the workload. 
+    For more detail, see the description
     <a href="job-scheduling.html#dynamic-resource-allocation">here</a>.
     <br><br>
     This requires <code>spark.shuffle.service.enabled</code> to be set.