Too Long; Didn't Read
A README file is like your project’s cover letter and is very good practice with documentation and writing. It will help you focus on explaining what your project's main goal is and how you want to achieve it. The whole documentation doesn't need to be extra long, but it should explain the project well. If you have a blog and feel like creating a tutorial about the project or any specific technology involved in the project, you could link it here. Link your deployed final version so that anyone can see it and test its functionality.