* Add "Symfony 5: The Fast Track" book (en)
* Add "Symfony 5: The Fast Track" book (es)
* Add "Symfony 5: The Fast Track" book (de)
* Add "Symfony 5: The Fast Track" book (ar)
* Add "Symfony 5: The Fast Track" book (fa)
* Add "Symfony 5: The Fast Track" book (ja)
* Add "Symfony 5: The Fast Track" book (ru)
* Add "Symfony 5: The Fast Track" book (it)
* Add "Symfony 5: The Fast Track" book (nl)
* Add "Symfony 5: The Fast Track" book (pl)
* Add "Symfony 5: The Fast Track" book (pt_BR)
* Add "Symfony 5: The Fast Track" book (ro)
* Add "Symfony 5: The Fast Track" book (zh_CN)
* Add "Symfony 5: The Fast Track" book (fr)
* Remove redundant line breaks
* Fix the index
* Add Python Book (Arabic)
* Add CSS book (Arabic)
* Add HTML book (Arabic)
* Update ubuntu book’s link
Update ubuntu book’s link with the original source link
* Update UX book’s link
Update UX book’s link with the original source link