Add link to docs to README (alloy-rs#542)

While the GH repo's site is the docs page, that is off-center (and not rendered when viewing the repository via a cloned local view). I had to be explicitly told the docs site existed due to not noticing that location (nor any other which may or may not exist). Ideally, the README includes the link *somewhere*. This is a location with no changes to layout.

README.md

@@ -3,7 +3,7 @@
 Alloy connects applications to blockchains.
 
 Alloy is a rewrite of [`ethers-rs`] from the ground up, with exciting new
-features, high performance, and excellent docs.
+features, high performance, and excellent [docs](alloy-rs.github.io/alloy/).
 
 [`ethers-rs`] will continue to be maintained until we have achieved
 feature-parity in Alloy. No action is currently needed from devs.