Cleaned irregular files of no value

After seeing #251 , I got the idea to make a quick script that shows irregularities (files that are not in lang/en).

After cleaning those of no value, these are the rest:

ep01_Potion-of-Flight/lang/jb/todo.md
ep15_The-Crystal-Ball/lang/vi/DanhSáchTên.txt
ep17_A-Fresh-Start/lang/vi/DanhSáchTên.txt
ep21_The-Magic-Contest/lang/vi/HạtTiêu&CủĐỏ_DanhSáchTên.txt
ep22_The-Voting-System/lang/vi/HạtTiêu&CủĐỏ_DanhSáchTên.txt
ep38_The-Healer/lang/vi/README.md

And about that VI txt files, it seems that it was ported to vi.po.
I'm going to check what was not and port it, and then remove thoose txt files.

Update: Those from EP 15, 17, 21 seem outdated, I ported what I could (comments) to vi.po and renamed the resting one in EP22 to README.txt