Add a brief description.

dmbates · dmbates · commit 360cde3043b2 · 2019-01-09T14:16:42.000-06:00
diff --git a/README.md b/README.md
@@ -24,3 +24,5 @@
 
 [codecov-img]: https://codecov.io/github/dmbates/MixedModels.jl/badge.svg?branch=master
 [codecov-url]: https://codecov.io/github/dmbates/MixedModels.jl?branch=master
+
+This package defines the `LinearMixedModel` and `GeneralizedLinearMixedModel` types and methods to `fit!` them and examine the results.  Please see the documentation for details.
