Fix doc links

Arguably the doc links and root URL are wrong, but they
avoid broken links and will do for now.

Author: dhardy

src/lib.rs

@@ -91,6 +91,10 @@
 //! [15]: https://nodejs.org/api/crypto.html#crypto_crypto_randombytes_size_callback
 //! [16]: #support-for-webassembly-and-amsjs
 
+#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk.png",
+       html_favicon_url = "https://www.rust-lang.org/favicon.ico",
+       html_root_url = "https://rust-random.github.io/rand/")]
+
 #![no_std]
 
 #[cfg(not(target_env = "sgx"))]