Big small update ahead

It has been a while since I last updated this plugin.

There are still some little things that I think I will tweak with times, and I'm planning something for the release of Godot 4 (but I still have to try it, so we'll see how that will go). However, I'm pretty happy with how this plugin turned out.
To think it wasn't even supposed to be a plugin in the first place. I just needed a tool to avoid resetting the BGM of my game 50 Years Later at the start of every new level. And yet, here we are.

Anyway, you're probably wondering what has actually changed.

Not much, actually. This update has been on my mind for a long time now. Today I was testing the demo again to make sure that the plugin hadn't break with the release of Godot 3.4 and I decided to take this opportunity to finally make this change.

The Sound Manager is now licensed under MIT License.

Some of you are probably thinking "What are you even talking about?". Let me explain. You probably think that open-source software is just free to use with no license or requirement attached. Well, that's not actually the case. There are plenty of different open-source licenses, with some that grant more freedom than others. In particular, the license this plugin formerly used, the Mozilla Public License (or MPL) had the requirements that the plugin itself had to remain open-source, even inside a closed-source software.

I wasn't exactly against it.

Let me be clear on this. I advocate for the open-source. So of course I wasn't against this requirement. And yet, I felt like it was a bit too restrictive considering the scope of this software was to be used inside of games. Having to constantly remember to include a copy of the source code of the Sound Manager inside every project was a hassle I didn't want for the indie developers out there.

That's why from now on the Sound Manager is going to be licensed under the MIT License.

What does this new license require? Actually, almost nothing. The only request is that the license has to be included with all copies of this software. No source code needed, no nothing. Now you can freely use this plugin and everything inside it with absolutely no actual restriction.
The only part of this... ecosystem (if I may call it this way) that remained under MPL is the Demo because that particular software has a completely different scope and the MIT License is not really needed.

So that's it. No other update if not some minor changes in the configuration file of the plugin and the README file to state "Godot 3" instead of "Godot 3.3". You can now continue using this plugin as you did before. If not more freely than before.