[docs] - Project Description in README.md

### Description

Update `README.md` giving a better description of the project, under the existing headings, including the purpose, how to install and run, and how it is meant to function. If possible, screenshots of db design should be included

Start with README.md and review the existing headings. Identify the project's purpose, installation and run instructions, and intended behavior from the repository, then document those sections and include database-design screenshots if available. Done means the README gives a substantially clearer project overview and usage guide.

Written by the indexing model from the issue text.