add korean books

[maldron0309]

What does this PR do?

Add info

For resources

Description

Why is this valuable (or not)?

How do we know it's really free?

Available for free on website

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

book

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!

[github-actions[bot]]

Linter failed, fix the error(s):

  free-programming-books/books/free-programming-books-ko.md
   60:1-62:108  warning  Alphabetical ordering: swap l.62 and l.61    alphabetize-lists  remark-lint
  173:1-187:92  warning  Alphabetical ordering: swap l.185 and l.184  alphabetize-lists  remark-lint

[github-actions[bot]]

Linter failed, fix the error(s):

  free-programming-books/books/free-programming-books-ko.md
   60:1-62:108  warning  Alphabetical ordering: swap l.62 and l.61    alphabetize-lists  remark-lint
  173:1-187:92  warning  Alphabetical ordering: swap l.185 and l.184  alphabetize-lists  remark-lint

[eshellman]

Thanks, and welcome to free-programming-books!