feat: Add docs/readme.md + update crosslinks (#6700)

* complete translate list with the new languages appeared since hacktoberfest

* Create docs/README.md with the translations section

using root README.md as source. Links are adapted to this folder

Address EbookFoundation/free-programming-books#6698

* fix remaining url + translation items

- Portuguese (Portugal)
- Slovak / slovenčina
- Slovenian / slovenščina

Address EbookFoundation/free-programming-books#6698

* fix remaining url + translation items

- Portuguese (Portugal)
- Slovak / slovenčina
- Slovenian / slovenščina

Address EbookFoundation/free-programming-books#6698

* Add inclusiveness `dare to translate...` paragraph

* Add inclusiveness `dare to translate...` paragraph

* Move translations link target url to docs

* move translation links `bs`

* move translations link `en`

* move translations crosslink `es`

* move translations crosslink `fr`

* move translations crosslink `de`

* move translations crosslink `el`

* move translations crosslink `fa_IR`

* move translations crosslink `fil`

* move translations crosslink `it`

* move translations crosslink `pt_BR`

* move translations crosslink `ko`

* move translations crosslink `ru`

* move translations crosslink `id`

* move translations crosslink `zh`

* move translations crosslink `hi`

* move translations crosslink `pl`

* move translations crosslink `uk`

* move translations crosslink `vi`

* move translations crosslink remaining `HOW-To's`

* revert feature moved to #6688

* Remove the list from the top level. Leave `en` links

* use `previous languages` in root README

* Add more languages lists in root `readme.md`

* fix typo

* fix typo

* Update docs/README.md after translations paragraph

Less text is more

Co-authored-by: Eric Hellman <eric@hellman.net>

* Update README.md after translations paragraph 

Less text is more

Co-authored-by: Eric Hellman <eric@hellman.net>

* Update README.md preface translations paragraph 

Co-authored-by: Eric Hellman <eric@hellman.net>

* fix CONTRIBUTING target url commited at fd2b39151c

* Update docs/README.md preface translations paragraph 

Co-authored-by: Eric Hellman <eric@hellman.net>

* read me! said the boss ^^,

less text is more.

Co-authored-by: Eric Hellman <eric@hellman.net>

* remove "The inclusiveness is one of our targets, so "

Co-authored-by: Eric Hellman <eric@hellman.net>

docs/CONTRIBUTING-es.md

@@ -264,7 +264,7 @@ Si es posible imprimirlo y conservar su esencia, no es un Tutorial Interactivo.
 
 [license]: ../LICENSE
 [coc]: CODE_OF_CONDUCT-es.md
-[translations-list-link]: ../README.md#translations
+[translations-list-link]: README.md#translations
 [issues]: https://github.com/EbookFoundation/free-programming-books/issues
 [formatting]: #formato-normalizado
 [guidelines]: #pautas