Check for missing docs.

src/packages/mod.rs

@@ -97,6 +97,7 @@ macro_rules! def_package {
         }
 
         impl $package {
+            #[doc=concat!("Create a new `", stringify!($package), "`")]
             pub fn new() -> Self {
                 let mut module = $crate::Module::new();
                 <Self as $crate::packages::Package>::init(&mut module);