Add code comments

spatial/static/spatial/js/gridmap.js

@@ -193,6 +193,8 @@ msLoadMap(): Unable to access file. (/disks/data01/mapserver/wms/SEPTREFFUM/SEPT
     setCurrentDate(todayLayerIndex);
     switchLayer(todayLayerIndex);
 
+    // Set zoom and center either based on what the user previously had set,
+    // or fit the map to the layer's extent
     var storedMapSettings = getLocalSettings([
         "gridmap.longitude",
         "gridmap.latitude",
@@ -225,6 +227,7 @@ msLoadMap(): Unable to access file. (/disks/data01/mapserver/wms/SEPTREFFUM/SEPT
 
     map.on('singleclick', displayQueryResult);
 
+    // Store user's zoom/pan preferences for the next browser session
     map.on('moveend', function(evt) {
 		// Store map settings
 		var centerCoordinate = ol.proj.transform(map.getView().getCenter(), map.getView().getProjection().getCode(),'EPSG:4326');