7.1.4 A Gravatar image and a sidebar

The last element needed to complete the mockup from Figure 7.1 is the
initial version of the user sidebar. We’ll implement it using the aside
tag, which is used for content (such as sidebars) that complements the
rest of the page but can also stand alone. We include row and span4
classes, which are both part of Bootstrap. The code for the modified
user show page appears in Listing 7.14.