Add CodeIgniter Tutorials (ID) from GilaCoding.com (EbookFoundation#9567)

* add codeigniter tutorials

* fix author

---------

Co-authored-by: tubagus.maulana <[email protected]>

Author: maulanaaghnii

books/free-programming-books-id.md

@@ -55,6 +55,7 @@
 
 * [Codeigniter - Pendekatan Praktis](https://leanpub.com/codeigniter-pendekatanpraktis) - Ibnu Daqiqil Id (HTML, PDF, EPUB, Kindle) *(Membutuhkan akun Leanpub atau email yang valid)*
 * [Codeigniter Untuk Pemula](https://repository.bsi.ac.id/index.php/unduh/item/176695/Tutorial-Codeigniter-Untuk-Pemula.pdf) - M Fikri Setiadi (PDF)
+* [Framework Codeigniter - Sebuah Panduan dan Best Practice](https://gilacoding.com/upload/file/Tutorial%20framework%20codeigniter.pdf) - Gila Coding (PDF)
 * [Panduan Pengguna CodeIgniter Indonesia](https://codeigniter-id.github.io/user-guide/) - CodeIgniter Indonesia
 * [Tutorial CodeIgniter 3 & 4](https://www.petanikode.com/tutorial/codeigniter/) *(Dalam Proses)*
 * [Tutorial CodeIgniter 4](http://mfikri.com/artikel/tutorial-codeigniter4)