Release trpl 0.3

Merge pull request #4097 from rust-lang/new-baseline

Correct baseline after running update-rustc.sh again

infra: publish trpl@0.2.0 w/new features from edits

infra: prepare `trpl` crate for 0.1.0 release

Update and clarify some text affected by the rand update

code is 1024 now, not 512

reexport to re-export

Update more screenshots

one book to rule them all

Another match statement -> match expression