add stamen-terrain updates

Author: LiamConnors

doc/python/mapbox-density-heatmaps.md

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   plotly:
     description: How to make a Mapbox Density Heatmap in Python with Plotly.
     display_as: maps
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     thumbnail: thumbnail/mapbox-density.png
 ---
 
-#### Mapbox Access Token
-
-To plot on Mapbox maps with Plotly you _may_ need a Mapbox account and a public [Mapbox Access Token](https://www.mapbox.com/studio). See our [Mapbox Map Layers](/python/mapbox-layers/) documentation for more information.
-
-### Stamen Terrain base map (no token needed): density mapbox with `plotly.express`
+### Stamen Terrain base map (Stadia Maps token needed): density mapbox with `plotly.express`
 
 [Plotly Express](/python/plotly-express/) is the easy-to-use, high-level interface to Plotly, which [operates on a variety of types of data](/python/px-arguments/) and produces [easy-to-style figures](/python/styling-plotly-express/).
 
 With `px.density_mapbox`, each row of the DataFrame is represented as a point smoothed with a given radius of influence.
 
+To use the mapbox_style "stamen-terrain", you'll need a [Stadia Maps](https://www.stadiamaps.com) token, which you can provide to the `mapbox_accesstoken` parameter on `fig.update_layout`.
+
+Here, we have the token saved in a file called `.mapbox_token`, load it in to the variable `token`, and then pass it to `mapbox_accesstoken`.
+
+<!-- #region -->
 ```python
+import plotly.express as px
 import pandas as pd
+
+token = open(".mapbox_token").read() # you will need your own token
+
 df = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/earthquakes-23k.csv')
 
-import plotly.express as px
 fig = px.density_mapbox(df, lat='Latitude', lon='Longitude', z='Magnitude', radius=10,
                         center=dict(lat=0, lon=180), zoom=0,
                         mapbox_style="stamen-terrain")
+fig.update_layout(mapbox_accesstoken=token)
 fig.show()
 ```
+<!-- #endregion -->
+
+![Stamen terrain Plotly Express example](https://raw.githubusercontent.com/plotly/documentation/gh-pages/all_static/images/stamen-terrain-1.jpeg)
 
-### Stamen Terrain base map (no token needed): density mapbox with `plotly.graph_objects`
+
+### Stamen Terrain base map (Stadia Maps token needed): density mapbox with `plotly.graph_objects`
 
 If Plotly Express does not provide a good starting point, it is also possible to use [the more generic `go.Densitymapbox` class from `plotly.graph_objects`](/python/graph-objects/).
 
+<!-- #region -->
 ```python
+import plotly.graph_objects as go
 import pandas as pd
+
+token = open(".mapbox_token").read() # you will need your own token
+
 quakes = pd.read_csv('https://raw.githubusercontent.com/plotly/datasets/master/earthquakes-23k.csv')
 
-import plotly.graph_objects as go
 fig = go.Figure(go.Densitymapbox(lat=quakes.Latitude, lon=quakes.Longitude, z=quakes.Magnitude,
                                  radius=10))
-fig.update_layout(mapbox_style="stamen-terrain", mapbox_center_lon=180)
+fig.update_layout(mapbox_style="stamen-terrain", mapbox_center_lon=180, mapbox_accesstoken=token)
 fig.update_layout(margin={"r":0,"t":0,"l":0,"b":0})
 fig.show()
+
 ```
+<!-- #endregion -->
+
+![Stamen terrain Graph Objects example](https://raw.githubusercontent.com/plotly/documentation/gh-pages/all_static/images/stamen-terrain-2.jpeg)
+
 
 #### Reference