make boostrap buttons flat code example

Example 1: bootstrap disabled button

<button type="button" class="btn btn-lg btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary btn-lg" disabled>Button</button>

Example 2: bootstrap buttons

<button type="button" class="btn btn-primary">Blue</button>
<button type="button" class="btn btn-secondary">Grey</button>
<button type="button" class="btn btn-success">Green</button>
<button type="button" class="btn btn-danger">Red</button>
<button type="button" class="btn btn-warning">Orange</button>
<button type="button" class="btn btn-info">Navy Blue</button>
<button type="button" class="btn btn-light">Light Grey</button>
<button type="button" class="btn btn-dark">Black</button>

<button type="button" class="btn btn-link">Link</button>