add spark internal book (#6434)

* add spark internal book

* change slideshare like to forked repository

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

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

* update TOC

* change TOC title to group of content

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

* trigger linter

* remove typo

* Ordering TOC

* re-arrange book section

* more specific document to Thai version

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

Co-authored-by: David Ordás <3125580+davorpa@users.noreply.github.com>

Author: aorjoa

books/free-programming-books-th.md

@@ -1,11 +1,17 @@
 ### Index
 
+* [Apache Spark](#apache-spark)
 * [Go](#go)
 * [IoT (internet of things)](#iot-internet-of-things)
 * [Java](#java)
 * [Python](#python)
 
 
+### Apache Spark
+
+* [Spark Internals](https://github.com/JerryLead/SparkInternals/tree/HEAD/markdown/thai) - Lijie Xu, Bhuridech Sudsee
+
+
 ### Go
 
 * [ภาษา Go ตอน 1 ติดตั้ง และ Run Hello World](https://medium.com/odds-team/%E0%B8%AA%E0%B8%A3%E0%B8%B8%E0%B8%9B%E0%B8%81%E0%B8%B2%E0%B8%A3%E0%B9%80%E0%B8%A3%E0%B8%B5%E0%B8%A2%E0%B8%99%E0%B8%9E%E0%B8%B7%E0%B9%89%E0%B8%99%E0%B8%90%E0%B8%B2%E0%B8%99%E0%B8%A0%E0%B8%B2%E0%B8%A9%E0%B8%B2-go-%E0%B9%81%E0%B8%9A%E0%B8%9A-step-by-step-%E0%B8%88%E0%B8%B2%E0%B8%81-course-pre-ultimate-go-by-p-yod-%E0%B8%95%E0%B8%AD%E0%B8%99-1-%E0%B8%95%E0%B8%B4%E0%B8%94%E0%B8%95%E0%B8%B1%E0%B9%89%E0%B8%87-%E0%B9%81%E0%B8%A5%E0%B8%B0-d9ac7913e9a4) - 
@@ -26,4 +32,3 @@ Chaiyarin Niamsuwan
 ### Python
 
 * [Python ๑๐๑](https://www.cp.eng.chula.ac.th/books/python101/) - กิตติภณ พละการ, กิตติภพ พละการ, สมชาย ประสิทธิ์จูตระกูล , สุกรี สินธุภิญโญ
-