Move no_std attribute

Author: newpavlov

hex-literal/src/lib.rs

@@ -1,5 +1,5 @@
-#![doc = include_str!("../README.md")]
 #![no_std]
+#![doc = include_str!("../README.md")]
 #![doc(
     html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg"