Structural Roles Section: Add deletion and insertion roles (pull #1140)

Resolve issue #1107 by adding insertion and deletion to the table of structural roles.

aria-practices.html

@@ -5024,13 +5024,15 @@ <h2>Structural Roles</h2>
         <tr><th>code</th><td>code</td></tr>
         <tr><th>columnheader</th><td>th</td></tr>
         <tr><th>definition</th><td>dd</td></tr>
+        <tr><th>deletion</th><td>del</td></tr>
         <tr><th>directory</th><td>No equivalent element</td></tr>
         <tr><th>document</th><td>No equivalent element</td></tr>
         <tr><th>emphasis</th><td>em</td></tr>
         <tr><th>feed</th><td>No equivalent element</td></tr>
         <tr><th>figure</th><td>figure</td></tr>
         <tr><th>group</th><td>No equivalent element</td></tr>
         <tr><th>heading with aria-level="N" where N is 1, 2, 3, 4, 5, or 6</th><td>h1, h2, h3, h4, h5, h6</td></tr>
+        <tr><th>insertion</th><td>ins</td></tr>
         <tr><th>img</th><td>img</td></tr>
         <tr><th>list</th><td>ul, ol</td></tr>
         <tr><th>listitem</th><td>li</td></tr>