update s element mapping

closes #416 

revises the `<s>` element to map to ARIA's `deletion` role, rather than having no implicit ARIA mapping.
Introducing this mapping would allow for browsers to expose this role, and thus AT to better communicate that the content is marked as no longer relevant.  Presently authors need to employ visually hidden content to programmatically convey what the element visually represents with its default UA CSS strike-through.

index.html

@@ -2659,33 +2659,13 @@ <h3>HTML Element Role Mappings</h3>
             </tr>
             <tr tabindex="-1" id="el-s">
               <th><a data-cite="HTML">`s`</a></th>
-              <td class="aria">No corresponding role</td>
-              <td class="ia2">
-                <div class="general">No accessible object.</div>
-                <div class="properties">
-                  <span class="type">Text attributes:</span> `text-line-through-style:solid` on the text container
-                </div>
-              </td>
-              <td class="uia">
-                <div class="general">No accessible object. Styles used are exposed by UIA text attribute identifiers of the `TextRange` Control Pattern implemented on a parent accessible object.
-                </div>
-              </td>
-              <td class="atk">
-                <div class="general">No accessible object. Exposed as
-                  "text-line-through-style:solid" text attribute on the text container.
-                </div>
-              </td>
-              <td class="ax">
-                <div class="role">
-                  <span class="type">AXRole:</span> `AXGroup`
-                </div>
-                <div class="subrole">
-                  <span class="type">AXSubrole:</span> `(nil)`
-                </div>
-                <div class="roledesc">
-                  <span class="type">AXRoleDescription:</span> `"group"`
-                </div>
+              <td class="aria">
+                <a class="core-mapping" href="#role-map-deletion">`deletion`</a> role
               </td>
+              <td class="ia2"><div class="general">Use WAI-ARIA mapping</div></td>
+              <td class="uia"><div class="general">Use WAI-ARIA mapping</div></td>
+              <td class="atk"><div class="general">Use WAI-ARIA mapping</div></td>
+              <td class="ax"><div class="general">Use WAI-ARIA mapping</div></td>
               <!-- <td class="naming"></td> -->
               <td class="comments"></td>
             </tr>