Create "Roll the dice" example application

[pellared]

Part of open-telemetry/opentelemetry.io#2623

Steps:

1. Create "Roll the dice" example application in this repository (Add dice example #4539)
2. Update https://opentelemetry.io/docs/instrumentation/go/getting-started/ (Go: Roll the dice opentelemetry.io#3310)
3. Deprecate go.opentelemetry.io/otel/example/fib (Deprecate example/fib #4618)
4. (release) (https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.20.0)
5. Remove go.opentelemetry.io/otel/example/fib from the repository (Remove example/fib #4723)