Added a free Interactive Bootstrap tutorial by Scrimba

[Ajay-singh1]

What does this PR do?

Add resource(s) | Remove resource(s) | Add info | Improve repo Add Resources

For resources

It is a tutorial

Description

Added an interactive tutorial for Bootstrap by Scrimba

Why is this valuable (or not)?

Yes

How do we know it's really free?

The tutorial is completely free mentioned on the website.

For book lists, is it a book? For course lists, is it a course? etc.

It is an interactive tutorial

Checklist:

• [x] Read our contributing guidelines.
• [x] Search for duplicates.
• [x] Include author(s) and platform where appropriate.
• [x] Put lists in alphabetical order, correct spacing.
• [x] Add needed indications (PDF, access notes, under construction).
• [x] Used an informative name for this pull request.

Follow-up

• Check the status of GitHub Actions and resolve any reported warnings!