0.7.1

Enhance caching functionality and update documentation

• Introduced per_instance parameter to the cache decorator, allowing shared caching between instances when set to False.
• Updated README to reflect the new caching behavior and added examples for clarity.
• Incremented version number to 0.7.1 in setup.cfg to signify the new feature addition.
• Expanded API reference documentation to include details about the per_instance parameter.

These changes improve the flexibility of the caching mechanism and enhance user understanding of its capabilities.

Full Changelog: 0.7.0...0.7.1