restoring styling to filled area on maps doc and restoring it to js maps index page

Author: Joseph Damiba

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

@@ -6,6 +6,7 @@
 thumbnail: thumbnail/area.jpg
 language: plotly_js
 has_thumbnail: true
+page_type: u-guide
 display_as: maps
 order: 10
 ---