Add .gitignore and secure environment configuration

- Added comprehensive .gitignore to prevent sensitive data commits
- Removed .env from git tracking to protect API tokens
- Created .env.example template for users to copy and configure
- Updated README with secure setup instructions using .env.example
- Prevents accidental exposure of Discogs API tokens and other secrets

README.md

@@ -32,10 +32,13 @@ A FastAPI-based web application that allows users to search for different types
    - Go to [Discogs Developer Settings](https://www.discogs.com/settings/developers)
    - Create a new application or use an existing one
    - Generate a User Token
-   - Copy the `.env` file and add your token:
+   - Copy the example environment file and add your token:
    ```bash
-   # Edit .env file
-   DISCOGS_USER_TOKEN=your_discogs_user_token_here
+   # Copy the example file
+   cp .env.example .env
+   
+   # Edit .env file and add your actual token
+   DISCOGS_USER_TOKEN=your_actual_discogs_token_here
    DISCOGS_USER_AGENT=YourAppName/1.0 +http://yourwebsite.com
    ```