"Bonus content" section and installation change

-The files must now be extracted in a folder inside C: (see the game's page)

-Added a slide at the beginning 

-Changing language will now open slide 3 (main menu) of the other file instead of 2 (loading screen)

-Added "Bonus content" section with music (listen to all the curent tracks* and view the sheet music), upcoming features and unused elements

-Removed floating icons from the lvl 7 starting slide and moved them to unused elements/upcoming features

-Changed sound effect when accessing the bonus lvl slide and the "YOU WON" tutorial slide (applause was annoying af)

-Changed the hyperlinks for changing language and mode files

-Updated installation instructions

-I think that's it XD

* I'll put some animations when playing the tracks in a future update, and maybe pause buttons too (comment if you'd want those)