Added PL/SQL section, added info to SQL books, included Oracle8i doc

[flbjuniorx]

What does this PR do?

Add resource(s) | Add info | Improve repo

For resources

Description

Added a PL/SQL section
Included author and format information at SQL books

Why is this valuable (or not)?

Improved information, added a new section

How do we know it's really free?

Checked copyrights

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

Yes

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!

[eshellman]

this is a chapter, we want the book

[github-actions]

Oh no 😟! Conflicts have been found.

Please 🙏, take a moment and address the merge conflicts of your pull request before we can evaluate it again.

Thanks in advance for your effort and patience ❤️!

[eshellman]

Thanks, and welcome to free-programming-books!