all: Include create README in lib.rsso doctests are run

[hds]

Feature Request

Crates

All the crates in the tracing repo (except tracing-mock which is already done).

Motivation

The examples in the README files aren't tested. The README may diverge from the
top level crate documentation in lib.rs for each crate. There is currently a mix of
examples for current vs. future versions of each crate in the README, which may
confuse users.

Proposal

Follow the examples in #2362 and include the full contents of the README
into the docs in lib.rs. As most crates already have documentation in lib.rs,
the two cases will need to be consolidates.

Alternatives

We could also copy and paste the README text into lib.rs, but that's probably
less than ideal.

[davidbarsky]

For what it's worth, I think we should do this—it would cut down on the documentation burden tremendously.

[hawkw]

yup, i've wanted to do this for a while, but haven't had the time to work on it. if you're willing to put a PR together, that would be much appreciated!

[hds]

Yep, I've got it on my to do list. I remember we discussed this in the PR for the tracing-mock README and I kind of forgot about it for a while. But I remembered again and decided to create an issue this time so I wouldn't forget... again. (-;

[hawkw]

Cool, I'll go ahead and assign you, then!