show arrow on mini download list

src/ui/App.css

@@ -42,4 +42,20 @@ body {
   position: absolute;
   top: 40%;
   left: 12%;
+}
+
+.arrow-down {
+  width: 0; 
+  height: 0; 
+  border-left: 50px solid transparent;
+  border-right: 50px solid transparent;
+  border-top: 50px solid transparent;
+
+  /* Colored section */
+  border-top: 50px solid #fff;
+
+  position: fixed;
+  top: 73%;
+  left: 15%;
+  
 }

src/ui/App.tsx

@@ -71,6 +71,7 @@ class App extends React.Component<IProps, IState> {
               }}>
                 <DownloadList downloadManager={downloadHandler} />
               </MiniDialog>
+              <div className="arrow-down"></div>
             </div> : null
         }