Change "Language Feature Reference" table in demo docs

[pellared]

Related to open-telemetry/opentelemetry-specification#2866

Lots of the things documented under "Auto Instrumentation" are in fact about using "instrumentation libraries".

[cartermp]

I think this is incorrect since, at the very minimum, the Java service uses the autoinstrumentation agent.

[pellared]

I think this is incorrect since, at the very minimum, the Java service uses the autoinstrumentation agent.

But e.g. Go, .NET are using manual instrumentation libraries. Therefore the existing header is misleading.

And yes, Java is using autoinstrumentation agent to apply instrumentation libraries 😉

EDIT: I am going to add an additional column per @Kielek suggestion.

[pellared]

@cartermp I added a separate column. a3bdb57

However, I am not sure if it won't be more readable to remove the whole "Language Feature Reference" section and add more info in "Service Documentation" section. E.g.

- [Ad Service](services/ad/) (**Java**, Automatic Instrumentation, Manual Instrumentation)
- [Cart Service](services/cart/) (**.NET**, Instrumentation Libraries, Manual Instrumentation)
...

WDYT?

[Kielek]

Probably also https://github.com/open-telemetry/opentelemetry.io/blob/main/content/en/docs/demo/trace-features.md should be adjusted

[pellared]

And https://github.com/open-telemetry/opentelemetry.io/blob/main/content/en/docs/demo/metric-features.md as well