Add support for type checking using Sorbet

The majority of the code in Homebrew is written in Ruby which is a dynamic language. This means that types are checked when the code is run. My project aims to incorporate Sorbet, a static type checker which would provide the benefits of static type checking to a developer. Adding static type checking helps developers rectify potential errors before the actual runtime. It also provides faster debugging of pre-existing bugs even by new developers, as they can easily jump to class/method definitions without having prior knowledge of the directory structure of the project. Sorbet serves as a tool to reduce brittle code, increases a developer’s confidence in their work and is a great tool for refactoring. I believe that this project has a lot of potential and the impact that it is going to have on the overall development cycle is going to be huge.