title: Nested rows with bootstrap grid system?
body: <p>I want 1 larger image with 4 smaller images in a 2x2 format like this: </p>
  
  <p><img src="https://i.stack.imgur.com/tdxuMm.png" alt="Figure 1 Example"></p>
  
  <p>My initial thought was to house everything in one row. Then create two columns, and, in the second column, create two rows and two columns to create the 1x1 and 2x2 effect. </p>
  
  <p>However, this doesn't seem to be possible, or I am just not doing it correctly?</p>