* remove 2 ebook of [Linkers and Loaders], [Learn Python The Hard Way]. ref issue:#3091, #3062
* Fix Issue: #2993, Add book The Black Art of Programming.
* fix author name
* Add Ruby Tutorial For Beginners
Hi,
This adds a new free Ruby tutorial (HTML version), **optionally** visitors can download a PDF version of the book by entering an email address.
## What does this PR do?
Add Resource
### Description
Free Ruby tutorial / book for beginners in HTML format with multiple lessons, including installing Ruby, conditionals, loops & object-oriented programming.
### Why is this valuable
It's a complete Ruby tutorial for beginners that helps learn Ruby from scratch. Includes examples, clear explanations & exercises.
### How do we know it's really free?
I made it.
### For book lists, is it a book?
Yes.
### Checklist:
- [x] Not a duplicate
- [x] Included author(s) if appropriate
- [x] Lists are in alphabetical order
- [x] Needed indications added (PDF, access notes, under construction)
* Use Full Book Name
* Add PHP screencasts
* Correct the number of blank spaces
* Update free-podcasts-screencasts-pt_BR.md
* Alphabetical ordering
I didn't know all this rules to edit a file, my bad.
* Add Excel-vba Ebook repo.
* Add VBA Eboob Repo. and fix incorrect menu link.
* fix Wrong format line
* Fix incorrect markdown syntax.
* Refactor DB and Javascript menu ZH version md file.
Move 'MySQL, NoSQL, PostgreSQL' under menu: Language Agnostic(语言相关),
Delete a book link of [Google JSON 风格指南], it's a multiple repo. with [JSON 风格指南], 2 link is point to the same one page.
* Delete multiple ebook link
D1. [Redis 设计与实现](http://redisbook.com), wiich is the same as menu: NoSQL -> [Redis 设计与实现](http://redisbook.com)
D2. [The Little MongoDB Book 中文版](https://github.com/justinyhuang/the-little-mongodb-book-cn) wiich is the same as menu: NoSQL -> [The Little MongoDB Book](https://github.com/justinyhuang/the-little-mongodb-book-cn/blob/master/mongodb.md)
* Update comments description.
* remove multiple ebook link
* Fix machine chek issue(fix mistake link location of PostgreSQL)
* FIX machine checking [Do not use headings with similar content (544:1)]
* Fix machine checking [359:1-361:78 warning Alphabetical ordering: swap l.361 and l.360 alphabetize-lists]
* Update license warpping length to 80 characters.
* Update free-programming-books-es.md
Add Piensa en Perl 6 (Spanish translation of Think Perl 6)
* Update free-programming-books.md
Add another Perl 6 book. Nowadays Perl 6 is also known as Raku (https://marketing.perl6.org/id/1541379592/pdf_digital) and the name Rakudo refers to the only major Perl 6 compiler at the moment. Also update status of 'Using Perl 6'.
* Update free-programming-books.md
Alphabetize list
* add space to satisfy linter
* Update free-programming-books-es.md
