Add docs badges (#1379)

* Add wasmtime docs badge

* Add cranelift docs badge, closes #1160

Author: abrown

README.md

@@ -12,6 +12,7 @@
     <a href="https://github.com/bytecodealliance/wasmtime/actions?query=workflow%3ACI"><img src="https://github.com/bytecodealliance/wasmtime/workflows/CI/badge.svg" alt="build status" /></a>
     <a href="https://bytecodealliance.zulipchat.com/#narrow/stream/217126-wasmtime"><img src="https://img.shields.io/badge/zulip-join_chat-brightgreen.svg" alt="zulip chat" /></a>
     <img src="https://img.shields.io/badge/rustc-1.37+-green.svg" alt="min rustc" />
+    <a href="https://docs.rs/wasmtime"><img src="https://docs.rs/wasmtime/badge.svg" alt="Documentation Status" /></a>
   </p>
 
   <h3>

cranelift/README.md

@@ -12,6 +12,7 @@ into executable machine code.
 [![Fuzzit Status](https://app.fuzzit.dev/badge?org_id=bytecodealliance)](https://app.fuzzit.dev/orgs/bytecodealliance/dashboard)
 [![Chat](https://img.shields.io/badge/chat-zulip-brightgreen.svg)](https://bytecodealliance.zulipchat.com/#narrow/stream/217117-cranelift/topic/general)
 ![Minimum rustc 1.37](https://img.shields.io/badge/rustc-1.37+-green.svg)
+[![Documentation Status](https://docs.rs/cranelift/badge.svg)](https://docs.rs/cranelift)
 
 For more information, see [the documentation](docs/index.md).