moving access token paragraph to top of mapbox-layers example

Author: Joseph Damiba

r/2019-09-20-mapbox-layers.Rmd

@@ -33,6 +33,20 @@ library(plotly)
 packageVersion('plotly')
 ```
 
+### Mapbox Access Tokens and When You Need Them
+
+  The word "mapbox" in the trace names and `layout.mapbox` refers to the Mapbox.js open-source library. If your basemap in `layout.mapbox.style` uses data from the Mapbox *service*, then you will need to register for a free account at https://mapbox.com/ and obtain a Mapbox Access token. This token should be provided either in `mapboxAccessToken`  in `setPlotConfig` function, or as a variable that would be passed as an argument of `newPlot`.
+    If your `layout.mapbox.style` does not use data from the Mapbox service, you do *not* need to register for a Mapbox account.
+    <h6>Base Maps in `layout.mapbox.style`</h6>
+    The accepted values for `layout.mapbox.style` are one of the following tiles.
+    <ol>
+        <li> `"white-bg"` yields an empty white canvas which results in no external HTTP requests </li>
+        <li> `"open-street-map"`, `"carto-positron"`, `"carto-darkmatter"`, `"stamen-terrain"`, `"stamen-toner"` or `"stamen-watercolor"` yeild maps composed of *raster* tiles from various public tile servers which do not require signups or access tokens </li>
+        <li> `"basic"`, `"streets"`, `"outdoors"`, `"light"`, `"dark"`, `"satellite"`, or `"satellite-streets"` yeild maps composed of *vector* tiles from the Mapbox service, and *do* require a Mapbox Access Token or an on-premise Mapbox installation. </li>
+        <li> A Mapbox service style URL, which requires a Mapbox Access Token or an on-premise Mapbox installation. </li>
+        <li> A Mapbox Style object as defined at https://docs.mapbox.com/mapbox-gl-js/style-spec/ </li>
+    </ol>
+
 ### How Layers work in Mapbox Maps
 
   If your figure contains one or more traces of type `Scattermapbox`, `Choroplethmapbox` or `Densitymapbox`, the `layout` object in your figure contains configuration information for the map itself. The map is composed of various layers, of three different types.
@@ -131,20 +145,6 @@ p <- us_cities %>%
 p
 ```
 
-### Mapbox Access Tokens and When You Need Them
-
-  The word "mapbox" in the trace names and `layout.mapbox` refers to the Mapbox.js open-source library. If your basemap in `layout.mapbox.style` uses data from the Mapbox *service*, then you will need to register for a free account at https://mapbox.com/ and obtain a Mapbox Access token. This token should be provided either in `mapboxAccessToken`  in `setPlotConfig` function, or as a variable that would be passed as an argument of `newPlot`.
-    If your `layout.mapbox.style` does not use data from the Mapbox service, you do *not* need to register for a Mapbox account.
-    <h6>Base Maps in `layout.mapbox.style`</h6>
-    The accepted values for `layout.mapbox.style` are one of the following tiles.
-    <ol>
-        <li> `"white-bg"` yields an empty white canvas which results in no external HTTP requests </li>
-        <li> `"open-street-map"`, `"carto-positron"`, `"carto-darkmatter"`, `"stamen-terrain"`, `"stamen-toner"` or `"stamen-watercolor"` yeild maps composed of *raster* tiles from various public tile servers which do not require signups or access tokens </li>
-        <li> `"basic"`, `"streets"`, `"outdoors"`, `"light"`, `"dark"`, `"satellite"`, or `"satellite-streets"` yeild maps composed of *vector* tiles from the Mapbox service, and *do* require a Mapbox Access Token or an on-premise Mapbox installation. </li>
-        <li> A Mapbox service style URL, which requires a Mapbox Access Token or an on-premise Mapbox installation. </li>
-        <li> A Mapbox Style object as defined at https://docs.mapbox.com/mapbox-gl-js/style-spec/ </li>
-    </ol>
-
 #### Dark Tiles from Mapbox Service: Free Token Needed
 
 Here is a map rendered with the `"dark"` style from the Mapbox service, which requires an Access Token: