Update ReadMe & add screenshot image file & demo video

Add styling

Add fonts

Refactor AngryButton to manage state with useReducer

Move LightSwitchButton state logic to App component

Refactor so LightSwitchButton changes app background and the button

Add styling for Dark Mode

Add click event handler to update TextRepeaterButton component state

Add click event handler to update LightSwitchButton component state

Add click event handler to update the state of CounterButton component

Add click event handler to update the state of AngryButton component

Implement useState on TextRepeaterButton component

Implement useState on LightSwitchButton component

Implement useState on CounterButton component

Implement useState on AngryButton component