Add JavaDoc to NamespaceType. (#1754)

JAVA-5769

Author: vbabanin

driver-core/src/main/com/mongodb/client/model/changestream/NamespaceType.java

@@ -29,8 +29,17 @@
  * @mongodb.server.release 8.1
  */
 public enum NamespaceType {
+    /**
+     * The collection namespace type.
+     */
     COLLECTION("collection"),
+    /**
+     * The timeseries namespace type.
+     */
     TIMESERIES("timeseries"),
+    /**
+     * The view namespace type.
+     */
     VIEW("view"),
     /**
      * The other namespace type.