Add enhanced decorators and tests

Added new tracing decorators to

• automatically create Span Attributes for identified function parameters
• aid with retrieval and management of propagation context
  Also added accompanying tests

What's Changed

• Update copier template to 2.2.0 by @callumforrester in #11
• Add Decorators and tests by @keithralphs in #15

New Contributors

• @callumforrester made their first contribution in #11

Full Changelog: 0.1.1...0.1.2