feat: Add clock screen

- New screen for a ring clock
- Add a canvas with the first ring
- No functionality yet

source/style/demo.scss

@@ -14,4 +14,5 @@
 @use "modules/songbook/songbook_module";
 @use "modules/demo/demo_module";
 @use "modules/start";
+@use "modules/clock";
 // @use "modules/YOUR-MODULE/YOUR-FILES";