feat(Button): add tertiary variant

src/shared/ui/Button/types.ts

@@ -1,3 +1,3 @@
-export type ButtonVariant = 'primary' | 'secondary' | 'ghost' | 'outline' | 'icon';
+export type ButtonVariant = 'primary' | 'secondary' | 'tertiary' | 'ghost' | 'outline' | 'icon';
 export type ButtonSize = 'xs' | 'sm' | 'md' | 'lg' | 'xl';
 export type IconPosition = 'left' | 'right';