Add firmware signing and verification

tutorials/device-dashboard/full/dashboard.html

@@ -622,7 +622,7 @@ a, a:visited, a:link { text-decoration: none; }
                     <path d="M5 21h14" />
                   </svg>
                   Select .bin file
-                  <input type="file" accept=".bin" hidden data-upload="1" />
+                  <input type="file" accept=".bin" hidden data-ota="1" />
                 </label>
 
               </div>