Fix formatting in errata page

Author: marijnh

html/errata.html

@@ -94,7 +94,8 @@ <h2>Chapter 16</h2>
 <h2>Chapter 19</h2>
 
 <p><strong>Page 336</strong> <em>The State</em>: The text mentions the
-property `fillColor` where it should say `fillStyle` instead.
+property <code>fillColor</code> where it should
+say <code>fillStyle</code> instead.
 
 <h2>Chapter 20</h2>