Add initial project structure and tests for Elytra PIM Client

- Created pyproject.toml for project metadata and dependencies.
- Added requirements.txt for development and production dependencies.
- Implemented basic test structure in the tests module.
- Developed unit tests for ElytraClient, including Pydantic validation and error handling.

.env.example

@@ -0,0 +1,14 @@
+# Elytra PIM Client Configuration
+# Copy this file to .env and fill in your actual values
+
+# The base URL of the Elytra PIM API
+ELYTRA_BASE_URL=https://example.com/api/v1
+
+# Your API key for authentication
+ELYTRA_API_KEY=your-api-key-here
+
+# Request timeout in seconds (optional, default: 30)
+ELYTRA_TIMEOUT=30
+
+# Verify SSL certificates (optional, default: true)
+ELYTRA_VERIFY_SSL=true