reorganize files (#5199)

* reorganize files

1. make it easier to find files
2. reduce scrolling to get to README on main view of repo

* remove tr.txt again

books/free-programming-books-dk.md

@@ -0,0 +1,32 @@
+### Index
+
+* [C](#c)
+* [C#](#c-sharp)
+* [C++](#c-1)
+* [Java](#java)
+* [Pascal](#pascal)
+
+
+### C
+
+* [Programmering i C](http://people.cs.aau.dk/~normark/c-prog-06/pdf/all.pdf) - Kurt Nørmark (PDF)
+
+
+### C Sharp
+
+* [Object-oriented Programming in C#](http://people.cs.aau.dk/~normark/oop-csharp/pdf/all.pdf) - Kurt Nørmark (PDF)
+
+
+### C++
+
+* [Notes about C++](http://people.cs.aau.dk/~normark/ap/index.html) - Kurt Nørmark (HTML)
+
+
+### Java
+
+* [Objektorienteret programmering i Java](http://javabog.dk) - Jacob Nordfalk
+
+
+### Pascal
+
+* [Programmering i Pascal](http://people.cs.aau.dk/~normark/all-basis-97.pdf) - Kurt Nørmark (PDF)