put images after line break (#219)

Author: pancakereport

chapters/02/1/observation-and-visualization-john-snow-and-the-broad-street-pump.md

@@ -37,6 +37,7 @@ map*. On a street map of the district, he recorded the location of each death.
 Here is Snow’s original map. Each black bar represents one death. When there are multiple deaths at the same address, the bars corresponding to those deaths are stacked on top of each other. The black
 discs mark the locations of water pumps. The map displays a striking
 revelation—the deaths are roughly clustered around the Broad Street pump.
+
 ![Snow’s Cholera Map](../../../images/snow_map.jpg)
 
 Snow studied his map carefully and investigated the apparent anomalies. All of

chapters/02/2/snow-s-grand-experiment.md

@@ -10,6 +10,7 @@ River Thames. Its water was relatively clean. But the Southwark and Vauxhall
 contaminated.
 
 The map below shows the areas served by the two companies. Snow honed in on the region where the two service areas overlap.
+
 ![Snow’s Other Map](../../../images/snow_map2.jpg)
 
 Snow noticed that there was no systematic difference between the people who were