add README.md file

README.md

+# Distributed Calculator System
+
+A distributed calculator system built with gRPC and multiple programming languages. This project demonstrates microservices architecture with three independent services communicating via gRPC.
+
+## 📋 Prerequisites
+
+- **Python 3.11+** (Client Gateway)
+- **Go 1.21+** (Addition Service) 
+- **Node.js 18+** (Multiplication Service)
+- **Protocol Buffers Compiler (protoc)**
+
+## 🚀 Quick Start
+
+### 1. Clone the repository
+```bash
+git clone <repository-url>
+cd distributed-calculator
+
+## How to Run Each Service
+
+- **Addition Service (Go)**
+  - Navigate to the service directory: `cd addition-service`
+  - Download dependencies: `go mod download`
+  - Run the service: `go run main.go`
+  - Expected Output:
+    ```
+    Addition Service running on port 50052
+    Ready to receive addition requests...
+    ```
+
+- **Multiplication Service (Node.js)**
+  - Navigate to the service directory: `cd multiplication-service`
+  - Install dependencies: `npm install`
+  - Run the service: `npm start`
+  - Expected Output:
+    ```
+    Multiplication Service (Node.js) running on port 50053
+    Ready to receive multiplication requests...
+    Powered by Node.js
+    ```
+
+- **Client Gateway (Python)**
+  - Navigate to the gateway directory: `cd client-gateway`
+  - Install dependencies: `pip install grpcio grpcio-tools`
+  - Run the gateway: `python client_gateway.py`
+  - Expected Output:
+    ```
+    Distributed Calculator System
+    1. Perform calculations
+    2. Show operation history
+    3. Exit
+    Choose option:
+    ```
+
+## How to Test the Connection Between Services
+
+- After running all services, you can test the connection between them by using the client gateway to perform calculations.
+- When choosing "Perform calculations", you will need to enter the type of operation (add or multiply) and the values.
+- If the services are working correctly, the gateway will send a request to the appropriate service and return the result.
+
+## Example Input and Output
+
+- **Input:**
+  ```
+  Choose option: 1
+  Enter operation (add/multiply): add
+  Enter first number: 5
+  Enter second number: 3
+  ```
+
+- **Output:**
+  ```
+  Result: 8
+  ```
+
+- **Input:**
+  ```
+  Choose option: 1
+  Enter operation (add/multiply): multiply
+  Enter first number: 4
+  Enter second number: 6
+  ```
+
+- **Output:**
+  ```
+  Result: 24
+  ```