Use docs hub in favor of book

[bitzoic]

Type of change

• Improvement (refactoring, restructuring repository, cleaning tech debt, ...)
• Documentation

Changes

The following changes have been made:

• Removes the Sway-Libs book deployment from CI
• All instances mentioning the Sway-Libs book now refer to the docs hub
• Removes the Libraries Overview libraries.md page in the book in favor of a more extensive index.md home page.
• Updates all links for Sway-Standards to use the docs hub over the repository

Notes

• Now that the sway-lib docs hub exists, we no longer need to book.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.