feat: Added Three.js section

[Sharmaji513]

What does this PR do?

Add resource(s) #11709

For resources

Description

This PR adds a new course resource for learning Three.js, a popular JavaScript library used for creating and displaying animated 3D graphics in a web browser.

Why is this valuable (or not)?

This course is valuable because it provides an accessible introduction to Three.js, enabling developers to enhance their web applications with interactive 3D graphics, which can significantly improve user engagement and experience.

How do we know it's really free?

The course is offered on Youtube and is clearly marked as free for anyone to access.

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

This entry is a course that teaches Three.js fundamentals.

Checklist:

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

Follow-up

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

[github-actions]

Linter failed, fix the error(s):

free-programming-books/courses/free-courses-hi.md
  498:1-501:3  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
505:1-506:118  warning  Alphabetical ordering: swap l.506 and l.505                            alphabetize-lists  remark-lint