Merge pull request #626 from herbie-fp/doc-tweaks

Pass on basically all documentation pages

Author: pavpanchekha

www/doc.html

@@ -33,13 +33,18 @@ <h2>Tutorials</h2>
   <h2>Documentation</h2>
 
   <ul>
-    <li><a href="doc/latest/faq.html">FAQ</a>: troubleshooting Herbie.</li>
-    <li><a href="doc/latest/release-notes.html">Release Notes</a>: the biggest and latest changes to Herbie.</li>
     <li><a href="doc/latest/input.html">Input format</a>: what sorts of expressions Herbie supports.</li>
     <li><a href="doc/latest/options.html">Command-line flags</a>: modifying Herbie's behavior.</li>
+    <li><a href="doc/latest/error.html">What is error?</a>: how Herbie measures floating-point error.</li>
+    <li><a href="doc/latest/faq.html">FAQ</a>: troubleshooting Herbie.</li>
+    <li><a href="doc/latest/release-notes.html">Release Notes</a>: the biggest and latest changes to Herbie.</li>
+  </ul>
+
+  <h2>Internal Documentation</h2>
+  <ul>
     <li><a href="doc/latest/plugins.html">Plugins</a>: teaching Herbie about new input formats.</li>
-    <li><a href="doc/latest/diagrams.html">Diagrams</a>: miscellaneous figures related to Herbie</li>
     <li><a href="doc/latest/api-endpoints.html">HTTP API</a>: Herbie's HTTP endpoints</li>
+    <li><a href="doc/latest/diagrams.html">Diagrams</a>: miscellaneous figures related to Herbie</li>
   </ul>
 
   <h2>Blog posts about Herbie</h2>