docs: Improve install guide for modern use like in scss.

[damil42]

Importing bootstrap and bootstrap-icons in your project is very simple. Simpler than in docs. And some docs are missing in bootstrap-icons.

your.scss

@import 'bootstrap';
@import 'bootstrap-icons';

Done! 👍

We could improve the docs / quick guide:

-https://getbootstrap.com/docs/5.3/getting-started/vite/#import-bootstrap
-https://icons.getbootstrap.com/#install

Currently there is the following in bootstrap docs:

@import "bootstrap/scss/bootstrap";

Which also works, but not necessary for a quick guide. In detail guide we can go deeper.

And for bootstrap-icon there is nothing about scss use. Only CDN, etc. It would be great if we complete this with a short scss guide.

We could also just provide a small quick guide section for use in scss in readme. In this example I use the proper keyword use instead of import. Read more what is wrong with import. In the case you only import once, the import method is ok. But in general prefer use instead.

@use 'bootstrap';
@use 'bootstrap-icons';

Why this issue? Because I had some difficulty bringing this to life. I wish there is a quick guide for modern use like in Angular with scss, etc. Just a tiny section with the code block about would save a lot time. It's great that this is so easy to use. Let the users know. Less is more. Best practices.