Update opentelemetry.io docs for auto instrumentation once ready

[aabmass]

https://opentelemetry.io/docs/instrumentation/python/automatic/

[srikanthccv]

@aabmass we have metrics instrumentation support for flask. I think we can update this now?

[lzchen]

@srikanthccv @aabmass
Is this issue pertaining to auto-instrumentation docs for metrics collection? It's not clear by title.

[emdneto]

@aabmass can we close this?