Use better font for the test UI

Author: jelveh

src/puter-js/test/run.html

@@ -6,6 +6,9 @@
     <script src="./fs.test.js"></script>
     <script src="./ai.test.js"></script>
     <style>
+        body {
+            font-family: Arial, sans-serif;
+        }
         #tests {
             margin-top: 20px;
         }