* feat: move all pages to app folder, add splashscreen
* feat: use Dance as splashscreen
* feat: add zoom in for splashscreen logo
* refactor: move svelte files into app folder
* fix: url prefix with /app
* refactor: remove platform-specific tauri conf
Merge windows back to main tauri config. The reason I separated them was
because I need decoration: true on mac and false on windows and linux.
Now I use tauri rust API to set decorations to false for win and linux.