Ruby Docs out of date

[willarmiros]

Current Ruby docs: https://aws-otel.github.io/docs/getting-started/ruby-sdk/trace-manual-instr

Per this SO post, the version numbers and, due to subsequent breaking changes, code snippets are incorrect.

We should:

1. Update https://github.com/aws-observability/aws-otel-ruby to use latest version
2. Update the docs to use latest APIs

[mhausenblas]

Agreed and let's discuss