docs(readme): add readme file about the project

Root readme file contains task completion status, as well as intruction
on how to run project in development stage using docker compose

backend/README.md

@@ -0,0 +1,24 @@
+# Backend
+
+This directory contains the backend server for the application.
+
+## Purpose
+
+The backend is a WebSocket server that provides real-time data to the frontend. It also serves as a simple API to get the history of the data.
+
+## Project Structure
+
+```
+.
+├── classes
+│   └── HistoryFile.js  # HistoryFile class, that provides easy way to save, and read history data
+├── consts.js           # Contains constants for the application
+├── data.json           # History file
+├── index.js            # Entrypoint for backend server
+├── nodemon.json        # Nodemon configuration file (used inside of docker)
+├── package-lock.json
+├── package.json
+├── README.md
+└── utils
+    └── random.js       # Utility that provides random data for backend
+```