more doc update

doc/en/user/source/extensions/mapml/template.rst

@@ -113,7 +113,7 @@ This would result in a MapML feature output header that would resemble:
     </mapml->
 
 The mapml-feature.ftl is a file can be used to insert map-style elements with the style class definitions into the map-head.  Note that this section of the template adds the styles listed but does not remove any existing styles.
-It can be used to edit map-property names and values in a manner similar to :ref:`tutorials_getfeatureinfo_geojson`.  It also can be used to add style class identifiers to map-feature elements based on the feature identifier or to wrap groupings of map-coordinates with spans that specify the style class based on an index of coordinate order (zero based index that starts at the first coordinate pair of each feature).  
+It can be used to edit map-property names and values in a manner similar to :ref:`tutorials_getfeatureinfo_geojson`.  Note that this template represents a full replacement of the feature.  If there are attributes that need to be included without change, they need to be referenced in the template.  It also can be used to add style class identifiers to map-feature elements based on the feature identifier or to wrap groupings of map-coordinates with spans that specify the style class based on an index of coordinate order (zero based index that starts at the first coordinate pair of each feature).  
 This file is placed in the GeoServer data directory in the directory for the layer we wish to append style classes to.  For example we could create the file under ``workspaces/tiger/poly_landmarks_shapefile/poly_landmarks``.  
 
 An example mapml-feature.ftl file to modify a point layer would look like::