Added Luxembourgish translation
Removed contrib folder, renamed some folders, removed duplicate lesson 06
Renamed lesson 3
[lb] Added lesson 9
Merge pull request #2 from mweimerskirch/lessons_3_and_9

Lessons 3 and 9
[lb] Renamed some files into their Luxembourgish equivalents
[lb] translated code blocks for lessons 1 and 7 into German
[lb] Renamed markdown file for lesson 2 to luxembourgish
[lb-LU] A few tweaks and corrections + Translated code blocks to German
Merge pull request #1 from mweimerskirch/lessons_3_and_9

[lb-LU] A few tweaks and corrections + Translated code blocks to German
Merge pull request #23 from CodeClubLux/master

Add Luxembourgish translation