public/manifest: change display to "standalone"

"fullscreen" is for immersive apps like games (and is only available
on Android currently which is why we didn't notice the app going
fullscreen on desktop).

Fixes: https://github.com/pybricks/support/issues/867

CHANGELOG.md

@@ -7,6 +7,11 @@
 ### Added
 - Added audio and visual feedback when typing into terminal while user program is not running.
 
+### Changed
+- Changed app display from "fullscreen" to "standalone" ([support#867]).
+
+[support#867]: https://github.com/pybricks/support/issues/867
+
 ## [2.0.1] - 2022-12-21
 
 ### Fixed

public/manifest.json

@@ -21,7 +21,7 @@
         }
     ],
     "start_url": ".",
-    "display": "fullscreen",
+    "display": "standalone",
     "theme_color": "#000000",
     "background_color": "#ffffff"
 }