docs: revert to static PNG for README and website hero

Author: DLhugly

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-  <img src="Clif.gif" alt="Clif" width="800" />
+  <img src="SplashScreen.png" alt="Clif" width="800" />
 </p>
 
 <h1 align="center">Clif</h1>

www/index.html

@@ -260,7 +260,7 @@ <h1>Code editor.<br><span class="thin">Not a browser.</span></h1>
       </p>
 
       <div class="screenshot">
-        <img src="https://raw.githubusercontent.com/DLhugly/Clif/main/Clif.gif" alt="Clif editor demo">
+        <img src="https://raw.githubusercontent.com/DLhugly/Clif/main/SplashScreen.png" alt="Clif editor demo">
       </div>
     </div>
   </section>