Add LICENSE file and update README.md for GPL-3.0 compliance

- Introduced the GNU General Public License v3.0 to ensure the software remains free and open source.
- Updated README.md to reflect the new licensing terms and added a section explaining the implications of the GPL-3.0 license.
- Included a brief description of the project's purpose as a test for AI-assisted software development.

README.md

@@ -6,6 +6,8 @@ A Rust-based API service that manages and provides information about hospitals o
 
 This API service tracks which hospital is currently on duty in Luxembourg City and provides endpoints to access this information. The system automatically manages hospital shifts and ensures there's always a hospital assigned for emergency services.
 
+This project was developed as a test project for exploring AI-assisted software development. It demonstrates how AI can be used to create, modify, and maintain a real-world application.
+
 ## Features
 
 - **Automatic Shift Management**: Creates and manages hospital shifts automatically
@@ -46,32 +48,6 @@ This API service tracks which hospital is currently on duty in Luxembourg City a
   }
   ```
 
-## Setup and Installation
-
-### Prerequisites
-
-- Rust (latest stable version)
-- PostgreSQL database
-- Environment variables (see Configuration section)
-
-### Installation
-
-1. Clone the repository:
-   ```bash
-   git clone https://github.com/yourusername/hospitalapi.git
-   cd hospitalapi
-   ```
-
-2. Build the project:
-   ```bash
-   cargo build --release
-   ```
-
-3. Run the application:
-   ```bash
-   cargo run
-   ```
-
 ## Configuration
 
 The application uses environment variables for configuration. Create a `.env` file in the project root with the following variables:
@@ -105,7 +81,14 @@ All system events are logged with timestamps in the format:
 
 ## License
 
-[MIT License](LICENSE)
+This project is licensed under the GNU General Public License v3.0 (GPL-3.0). This license ensures that:
+
+- The software remains free and open source
+- Any modifications or improvements must be shared back with the community
+- The source code must be made available to users
+- The license terms must be preserved in any derivative works
+
+For the full license text, see the [LICENSE](LICENSE) file.
 
 ## Contributing