Add a style for images.

Author: paveloom

sass/_base.scss

@@ -164,6 +164,13 @@ ul {
   }
 }
 
+img {
+  box-sizing: border-box;
+  max-width: 100%;
+  max-height: 50ch;
+  padding: 1em;
+}
+
 footer {
   margin-top: 3rem;
   font-size: 0.75em;