Increase jumbotron height

This height increase ensures that all faces in jumbotron images can be
seen even in widescreen! :)
Signed-off-by: Ethan Madison <ethan@ethanmad.com>

static/css/bootie-docs.css

@@ -57,7 +57,7 @@ pre code {
     position: relative;
     top: -20px;
     background-position: 0% 0%;
-    height: 350px;
+    height: 420px;
     background-size: cover;
     background-repeat: no-repeat;
     color: white;