부트스트랩 게시판 버튼 출력

<button type="button" class="btn btn-primary">Primary</button>

<button type="button" class="btn btn-secondary">Secondary</button>

<button type="button" class="btn btn-success">Success</button>

<button type="button" class="btn btn-danger">Danger</button>

<button type="button" class="btn btn-warning">Warning</button>

<button type="button" class="btn btn-info">Info</button>

<button type="button" class="btn btn-light">Light</button>

<button type="button" class="btn btn-dark">Dark</button>

Primary Secondary Success Danger Warning Info Light Dark Link

 <a class="btn btn-primary" href="#" role="button">Link</a>

 Link

 <a class="button" class="btn btn-primary btn-lg">Large button</a>