Clean up trailing whitespaces

- Remove trailing whitespaces from all .nix files
- Remove trailing whitespaces from shell scripts
- Remove trailing whitespaces from README files
- Improves code consistency and follows best practices

assets/alacritty/README.md

@@ -88,7 +88,7 @@ The solution uses Nix's conditional configuration in `home.nix`:
 ```nix
 colors = let
   isLightTheme = true;  # Change this to switch themes
-  
+
   lightColors = { /* Catppuccin Latte colors */ };
   darkColors = { /* Catppuccin Mocha colors */ };
 in if isLightTheme then lightColors else darkColors;