Error if the wrong architecture is being used

Author: lights0123

src/lib.rs

@@ -27,6 +27,12 @@
 pub mod interrupt;
 pub mod asm;
 
+#[cfg(not(any(doc, target_arch = "avr")))]
+compile_error!(
+    "Ensure that you are using an AVR target! You may need to change \
+directories or pass a --target flag to cargo."
+);
+
 #[allow(unused_imports)]
 use generic::*;
 #[doc = r"Common register and bit access and modify traits"]