Small update on the levels

Thanks to palsb14, I could change some of the levels of the demo. Here are the changes :

• Map : Made it way simpler to get to the extra level. I removed a level that could transform.
• Level 0 : No changes.
• Level 1 : No changes.
• Level 2 : Changed level name and way to win.
• Level 3 : Prevented belt transformation.
• Level 4 : Nerfed it.
• Level 5 : No changes.
• Level 6 : No changes.
• Level extra 1 : Added a couple pillars to prevent cheese.

I'll be working on the next world next.