Gatsby is great static site generator tool for react developers. Well, It can do a lot more than what static site generator does.
If you are very familier with bootstrap and love to create websites with bootstrap. You can do in gatsby site also..
But, When you about to add bootstrap to head tag in index.html in Public folder of gatsby, Like create-react-app.
Here, there is no such options to add CDN link to head tag.
But, you can install the bootstrap latest package with npm or yarn, you prefer. and import that in every page where you want!!
import 'bootstrap/dist/css/bootstrap.css';
Thanks for reading!!!