Review Documentation

[ffe4]

We should go over the docs to check for their accuracy, as well as, ideally, their usability.

There has also been discussion about including cross-language guides for setting up exporters on the website and creating requirements for SIG docs. However, there isn't a lot of activity in the Website SIG right now, so we might have to wait a bit on that.

[codeboten]

We should ensure environment variables supported are documented clearly as part of this work.

[lzchen]

As of 01/28/2021, the documentation for the 1.0.0 release has been reviewed. This includes docs for tracing api. tracing sdk, propagators, zipkin exporter, jaeger exporter, baggage and context.