Update doc.

doc/index.html

@@ -311,7 +311,9 @@ filter = tiny.requireAll("image", tiny.rejectAny("Player", "Enemy"))
     <h2 class="section-header has-description"><a name="System_functions"></a>System functions </h2>
 
           <div class="section-description">
-           A System is a wrapper around function callbacks for manipulating Entities.
+
+
+<p> A System is a wrapper around function callbacks for manipulating Entities.
  Systems are implemented as tables that contain at least one method;
  an update function that takes parameters like so:</p>
 
@@ -390,11 +392,17 @@ end
 
 <p> There is another option to (hopefully) increase performance in systems that
  have items added to or removed from them often, and have lots of entities in
- them.  Setting the <code>nocache&apos; field of the system might improve performance.
+ them.  Setting the <code>nocache</code> field of the system might improve performance.
  It is still experimental. There are some restriction to systems without
- caching, however.  * There is no </code>entities` table.  * Callbacks such onAdd,
- onRemove, and onModify will never be called * Noncached systems cannot be
- sorted (There is no entities list to sort).
+ caching, however.</p>
+
+<ul>
+    <li>There is no <code>entities</code> table.</li>
+    <li>Callbacks such onAdd, onRemove, and onModify will never be called</li>
+    <li>Noncached systems cannot be sorted (There is no entities list to sort).</li>
+</ul>
+
+
           </div>
     <dl class="function">
     <dt>
@@ -714,7 +722,7 @@ end
 </div> <!-- id="main" -->
 <div id="about">
 <i>generated by <a href="http://github.com/stevedonovan/LDoc">LDoc 1.4.3</a></i>
-<i style="float:right;">Last updated 2016-08-10 21:42:26 </i>
+<i style="float:right;">Last updated 2016-08-10 21:48:45 </i>
 </div> <!-- id="about" -->
 </div> <!-- id="container" -->
 </body>