Update to 2D platformer v1.2

This update fixes a bug that was causing the player to not detect ground under them at some places and was making the player stay in a jump or fall animation loop at that place. This has been fixed in this update. The ground detection code has been updated.
If this happens then the developer can open the extension source in a text editor and can increase the "max-height" constant to a higher value to fix the issue.