Set up local Sourcegraph OpenTelemetry development

General OpenTelemetry export configuration is done via environment variables according to the official configuration options specification.

Tracing

1. Set dev-private site config to use opentelemetry
2. sg start otel -> runs otel-collector and jaeger
3. sg start
4. Run a complex query with &trace=1, e.g. foobar(...) patterntype:structural
5. Click View trace