tweak the welcome screen (agh), note that it needs to be fixed

Author: benfry

build/shared/lib/icons/pde-1024.png

@@ -10,16 +10,16 @@
     <table>
       <tr>
         <td valign="top">
-          <img src="../icons/pde-64.png" width="64" height="64">
+          <img src="../icons/pde-128.png" width="64" height="64">
         </td>
         <td valign="middle">
-          <h1>Processing 4 (alpha)</h1>
+          <h1>Processing 4 (beta)</h1>
         </td>
       </tr>
     </table>
 
     <p>
-      <a href="https://github.com/processing/processing4/wiki/Changes-in-4.0">Read about what&rsquo;s new in 4.0 &rarr;</a>
+      <a href="https://github.com/processing/processing4/blob/master/README.md">Read about the status of the 4.0 release &rarr;</a>
     </p>
 
     <p class="inset">

build/shared/lib/icons/pde-128.png

@@ -10,21 +10,21 @@
     <table>
       <tr>
         <td valign="top">
-          <img src="../icons/pde-64.png" width="64" height="64">
+          <img src="../icons/pde-128.png" width="64" height="64">
         </td>
         <td valign="middle">
-          <h1>Processing 4 (alpha)
+          <h1>Processing 4 (beta)</h1>
         </td>
       </tr>
     </table>
 
     <p>
-      <a href="https://github.com/processing/processing4/wiki/Changes-in-4.0">Read about what&rsquo;s new in 4.0 &rarr;</a>
+      <a href="https://github.com/processing/processing4/blob/master/README.md">Read about the status of the 4.0 release &rarr;</a>
     </p>
 
     <p class="inset">
       Note that some sketches from Processing 2 or 3 may not be compatible.
-      <a href="https://github.com/processing/processing/wiki/Changes-in-4.0">What has changed?</a>
+      <a href="https://github.com/processing/processing4/wiki/Changes-in-4.0">What has changed?</a>
     </p>
 
     <div id="new_sketchbook">