Improve formatting of the help page a bit and update it

macrovision.css

@@ -473,7 +473,7 @@ body.toggle-bottom-name .bottom-name {
 #help ul {
     text-align: left;
     list-style: circle;
-    width: 75vw;
+    width: 75%;
 }
 
 #help li {

macrovision.html

@@ -50,10 +50,21 @@
     <h1>Adding/removing entities</h1>
     <p>
       <ul>
+        <li>Add new entities with the selection boxes at the top</li> 
         <li>Remove the selected entity with the Delete key</li>
         <li>Alternatively, drag them off the top of the screen</li>
       </ul>
     </p>
+    <h1>Sharing</h1>
+    <p>
+      <ul>
+        <li>You can copy a screenshot to your clipboard or save an image to your device in the topbar</li>
+        <li>To share a scene with others, you can get a link with the Permalink button</li>
+        <li>Alternatively, you can export the scene as text, or import one from your clipboard</li>
+        <li>You can also save one scene to your browser and load it later</li>
+        <li>The current scene is autosaved when closing the tool. You can reload it from the menu.</li>
+      </ul>
+    </p>
     <button id="close-help">Close</button>
   </div>
   <div id="popout-menu">

macrovision.js

@@ -1297,7 +1297,7 @@ function prepareMenu() {
     }
 }
 
-const lastHelpChange = 1585487259753;
+const lastHelpChange = 1587679987757;
 
 function checkHelpDate() {
     try {