Update readme and GitHub special files

[rudidev08]

Since smart shopping list is now proper GitHub project, I'd recommend making following changes:

• update readme to include how to install and run the app locally, and add a intro blurb that says what app does, bullet point list of features, high level libraries used (react, firebase, etc) and that it was developed as a Collab Lab project. Most of current readme contents should be removed
• remove contributors file and have authors mentioned in readme instead
• orientation file also looks like an extra, but up to you if to keep it or not
• project brief file can be removed too Above is my opinion, and feel free to change based on how you think project should be tidied up. There are also external references for project files, such as: https://github.com/joelparkerhenderson/github-special-files-and-paths