Stop splashscreen from being draggable

Author: Logicer16

Diff for: arduino-ide-extension/src/electron-main/splash/static/splash.html

@@ -12,6 +12,7 @@
         img {
             max-width: 95%;
             height: auto;
+            -webkit-user-drag: none;
         }
     </style>
 </head>