Instead of placing the link to the recommended resource i.e. the second
edition in second place, push it up to the top of the list. In fact,
push the link to the first edition always at the bottom.
To emphasise even more that's where new visitors should go, bolden the
first link, and make the first-ed link smaller.
All this as well as a slight edit and simplification of the copy is
designed to make the new and recommended resources the primary path
readers take, without hiding the old resource completely.
The second edition is a complete re-write. It is still under construction;
though it is far enough along to learn most of Rust; we suggest reading the
second edition and then checking out the first edition later to pick up some of
the more esoteric parts of the language.