Fix typo and add missing margin-bottom to tables

Author: GuillaumeGomez

_sass/_base.scss

@@ -25,11 +25,11 @@ body {
 
 
 /**
- * Set `margin-bottom` to maintain vertycal rhythm
+ * Set `margin-bottom` to maintain vertical rhythm
  */
 h1, h2, h3, h4, h5, h6,
 p, blockquote, pre,
-ul, ol, dl, figure,
+ul, ol, dl, figure, table,
 %vertical-rhythm {
     margin-bottom: $spacing-unit / 2;
 }