Update index.html

Author: arsx958

index.html

@@ -135,7 +135,7 @@ <h1>A Versatile Point Cloud Compressor<br/>
                               </a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
 
                                 <a href="./proposal.zip">
-                                <span style="font-size:20px" >Proposal </span>
+                                <span style="font-size:20px" >Proposals </span>
                               </a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                     </div>
                 </div>