Add MacOS/Linux support/tools

[rapito]

• Add required binaries to execute under MacOS and Linux
• Update Readme to include instructions for these platforms
• Created a Release on my fork with the binary and tools: https://github.com/rapito/gecko/releases/tag/v3.4.0

[JLaferri]

Hmm I don't think you should need to download those binaries manually. I'm pretty sure if you just install devkitPro with devkitPPC you should get the proper binaries in your path.

[rapito]

Yeah, thats what I had to do, but it took me so much time and trouble that I thought that simply including it is far better. The same as the windows build tool is already included and theres no need to install devkitppc. I would have definitely started working a lot sooner if it was not because of having to troubleshoot issues with devkit... This will help people who just want to do fast gecko code testing without installing too much stuff imo.