tweak to doc_header

Author: ablaom

src/metadata_utils.jl

@@ -213,7 +213,7 @@ function doc_header(SomeModelType)
 """
     $name
 
-Model type for $human_name, based on [$package_name]($package_url).
+Model type for $human_name, based on [$package_name]($package_url).jl.
 
 From MLJ, the type can be imported using
 

test/metadata_utils.jl

@@ -67,7 +67,7 @@ end
 FooRegressor
 ```
 
-Model type for foo regressor, based on [FooRegressorPkg](http://existentialcomics.com/).
+Model type for foo regressor, based on [FooRegressorPkg.jl](http://existentialcomics.com/).
 
 From MLJ, the type can be imported using