Add docs

Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "TestRepo"
+version = "0.1.0"

src/main.rs

@@ -1,3 +1,5 @@
+//! A test
+
 fn main() {
     println!("Hello, world!");
 }