Merge pull request #1545 from fredericksilva/lua

 add Lua org,Lua Tutorial, lua wikibook and lua interactive course 

free-courses-en.md

@@ -14,6 +14,7 @@
 * [iOS](#ios)
 * [Java](#java)
 * [JS](#js)
+* [Lua](#lua)
 * [Matlab](#matlab)
 * [Misc](#misc)
 * [OCaml](#ocaml)
@@ -103,6 +104,10 @@
 ### JS
 * [Egghead.io](https://egghead.io/)
 
+### Lua
+* [Lua Interactive Crash Course](http://luatut.com/crash_course.html)
+* [Lua Tutorial](http://www.tutorialpoint.com/lua/)
+* [Lua org](http://www.lua.org/)
 
 ### MATLAB
 * [MIT 18.S997 Introduction to MATLAB Programming](http://ocw.mit.edu/courses/mathematics/18-s997-introduction-to-matlab-programming-fall-2011/)

free-programming-books.md

@@ -1298,6 +1298,7 @@ See also [TeX](#tex)
 * [Lua 5.1 Reference Manual](http://www.lua.org/manual/5.1/)
 * [Programming In Lua](http://www.lua.org/pil/) (for version 5)
 * [Programming Gems](http://www.lua.org/gems/)
+* [Wikibook](http://en.wikibooks.org/wiki/Lua_Programming)
 
 
 ### Markdown