Documentation review

[OnorioCatenacci]

Just a small grammar correction. I believe that "Erlang" (in the cotext of the documentation) is a proper noun and should be capitalized. So I've modified tracing.livemd to do so.

Feel free to ignore me if I've gotten my grammar wrong.

[christhekeele]

Looks like some other stuff got mixed in here that is being merged in other PRs—closing accordingly