Add next js tutorial (#7773)

* Add next js tutorial

* Update books/free-programming-books-id.md

Co-authored-by: Biswadeep Purkayastha <98874428+metabiswadeep@users.noreply.github.com>

* Update free-programming-books-id.md

Co-authored-by: Biswadeep Purkayastha <98874428+metabiswadeep@users.noreply.github.com>
Co-authored-by: Eric Hellman <eric@hellman.net>

books/free-programming-books-id.md

@@ -13,6 +13,7 @@
 * [IDE and editors](#ide-and-editors)
 * [Java](#java)
 * [JavaScript](#javascript)
+    * [Next.js](#nextjs)
     * [React.js](#reactjs)
     * [Vue.js](#vuejs)
 * [Node.js](#nodejs)
@@ -115,6 +116,11 @@
 * [Tutorial JavaScript Pemrograman Berorientasi Objek](https://www.youtube.com/watch?v=SDROba_M42g) - Programmer Zaman Now
 
 
+#### Next.js
+
+* [Tutorial Next Js](https://santrikoding.com/kategori/next-js) - SantriKoding.com
+
+
 #### Vue.js
 
 * [Belajar Vue.js](https://variancode.com/belajar-vue-js/) - Varian Hermianto