Add documentation for the 3 other flags

All modern browsers support 5 RegExp flags so I have added documentation for them.

I have slightly refactored the Flags table, while preserving the current style.

Author: Daniel Arthur Gallagher

application.css

@@ -172,6 +172,7 @@ a:hover {
   margin-bottom: 20px;
 }
 
+#quick_reference th,
 #quick_reference td {
   padding-right: 15px;
   line-height:1.5em;
@@ -185,12 +186,6 @@ a:hover {
   width:60px;
 }
 
-#quick_reference a {
-  position: absolute;
-  top: 20px;
-  right: 20px;
-}
-
 input, textarea, #results, #groups {
   margin-bottom: 20px;
   background-color: white;
@@ -275,10 +270,6 @@ input, textarea, #results, #groups {
   padding-left: 30px;
 }
 
-#shares li {
-
-}
-
 #shares a {
   color: #444;
   font-size: 14px;

index.html

@@ -73,16 +73,33 @@ <h2>Share Link:</h2>
     </div>
 
     <div id="quick_reference">
-      <div class="scrollable">
-        <h2>Modifiers:</h2>
+      <div class="scrollable">        
         <table>
+          <caption><h2>Flags:</h2></caption>
           <tr>
-            <td class="regex">i</td>
+            <th class="regex">g</th>
+            <td>Perform a global match</td>
+          </tr>
+          <tr>
+            <th class="regex">i</th>
             <td>Perform case-insensitive matching</td>
           </tr>
           <tr>
-            <td class="regex">g</td>
-            <td>Perform a global match</td>
+            <th class="regex">m</th>
+            <td>Treat beginning and end characters (^ and $) as working over multiple lines</td>
+          </tr>
+          <tr>
+            <th class="regex">u</th>
+            <td>
+              Treat the pattern as a series of Unicode code points
+              (<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp#Regular_expression_and_Unicode_characters" rel="external noopener">
+                  See the MDN docs
+                </a>)
+            </td>
+          </tr>
+          <tr>
+            <th class="regex">y</th>
+            <td>Sticky; treat the pattern after a match as a separate pattern</td>
           </tr>
         </table>
         <h2>Brackets:</h2>