Update index.html

Author: Thorin-Oakenpants

index.html

@@ -37,6 +37,8 @@
 				<td>... you can run but you can't hide</td></tr>
 			<tr><td colspan="2"><a class="blue" href="tests/engineprop.html">engine properties</a></td>
 				<td>test: enumeration of engine properties</td></tr>
+			<tr><td colspan="2"><a class="blue" href="tests/os.html">os</a></td>
+				<td>test: gecko os detection logic</td></tr>
 			<tr><td colspan="2"><a class="blue" href="tests/versions.html">versions</a></td>
 				<td>a history of version pocs tzp uses or considered</td></tr>
 		<tr><td colspan="3"></td></tr>