changing layout to base for filled area on maps js example

Author: Joseph Damiba

_posts/plotly_js/maps/fill-area-on-mapbox/2019-09-02-fill-area_plotly_js_index.html

@@ -2,7 +2,7 @@
 name: Filled Area on Maps
 permalink: javascript/filled-area-on-mapbox/
 description: How to make an area on Map using a D3.js-based scattermapbox.
-layout: user-guide
+layout: base
 thumbnail: thumbnail/area.jpg
 language: plotly_js
 has_thumbnail: true