Create a primary button

[Utkarsh4517]

This marks the beginning of modular-ui

Things needed to be done:

1. create src folder inside lib

2. Inside src create buttons

3. Inside buttons folder create primary_button.dart

4. Under lib/modular_ui.dart export primary_button,dart -> This will act as the entrypoint for our package like this:

library modular_ui;

export 'src/buttons/primary_button.dart';