Second release of all images now with fixes 🎉

In this release:

• Replaced editor alias with unity-editor 🤘
• Added conditions to correctly build unity versions before 2019.3.x (without linux-il2cpp platform) 🌵
• Improved docs 📚

Changes

• #30
• #31
• #32
• #33

Credits

This is some amazing work 🎉. Special thanks to @jonathanperret and @webbertakken <3