update readme

Author: ablaom

README.md

@@ -15,9 +15,9 @@ Pkg.add("MLJTestIntegration")
 
 # Usage
 
-This package provides a single method for testing a collection of
-`models` (types or named tuples with keys `:name` and `:package_name`)
-using the specified training `data`:
+This package provides a method for testing a collection of `models`
+(types or named tuples with keys `:name` and `:package_name`) using
+the specified training `data`:
 
 ```julia
 MLJTestIntegration.test(models, data...; mod=Main, level=2, throw=false, verbosity=1) 
@@ -26,6 +26,16 @@ MLJTestIntegration.test(models, data...; mod=Main, level=2, throw=false, verbosi
 
 For detailed documentation, run `using MLJTestIntegration; @doc MLJTestIntegration.test`.
 
+For convenience, a number of specializations of this method are also provided: 
+
+- `test_single_target_classifiers`
+- `test_single_target_regressors`
+- `test_single_target_count_regressors`
+- `test_continuous_table_transformers`
+
+Query the document strings for details, or see
+[examples/bigtest/notebook.jl](examples/bigtest/notebook.jl).
+
 
 # Examples