test: Verify readme

Author: epage

src/lib.rs

@@ -4,3 +4,7 @@
 #![warn(clippy::print_stderr)]
 #![warn(clippy::print_stdout)]
 #![allow(non_snake_case)] // TODO: Delete me
+
+#[doc = include_str!("../README.md")]
+#[cfg(doctest)]
+pub struct ReadmeDoctests;