Add an Open Source License to the Project

[neurolag]

Hello, @Dannark
Currently, this repository doesn't contain an Open Source license.
Thus, this extension currently cannot be published to Eclipse's Open Source vscode Marketplace automatically.
Also, people forking your code and trying to keep working on your project might not know what they're allowed and not allowed to do with your code.

Websites like Choose A License will help you making a decision.

Could you please add an Open Source License file (LICENSE, LICENSE.txt) to your repository?

Thanks for your great work 😄