Minor update

Time for a minor update:

• Updated tutorials
• Added two new SFX template types: Tire Screech and Bell
  • They are currently in an early stage
• Improved save functionality and added Save As in context menu
• Showing messages when some actions are performed
• Bugfixes

The plan for next update is to improve usability when navigating the editor, such as when using the Alt-key. There are also stuff that can't be edited properly yet that can only be done with code, which I plan to keep working on.

Any suggestions for improving the usability would be highly valuable :)