rustup update notice

Author: steveklabnik

posts/2019-01-17-Rust-1.32.0.md

@@ -19,6 +19,9 @@ If you don't have it already, you can [get `rustup`][install] from the
 appropriate page on our website, and check out the [detailed release notes for
 1.32.0][notes] on GitHub.
 
+> As a small side note, `rustup` has seen some new releases lately! To update
+> `rustup` itself, run `rustup self update`.
+
 [install]: https://www.rust-lang.org/install.html
 [notes]: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1320-2019-01-17