Update README

Author: juliohm

README.md

@@ -1,6 +1,55 @@
 # StatsLearnModels.jl
 
-[![Build Status](https://github.com/JuliaML/StatsLearnModels.jl/actions/workflows/CI.yml/badge.svg?branch=main)](https://github.com/JuliaML/StatsLearnModels.jl/actions/workflows/CI.yml?query=branch%3Amain)
-[![Coverage](https://codecov.io/gh/JuliaML/StatsLearnModels.jl/branch/main/graph/badge.svg)](https://codecov.io/gh/JuliaML/StatsLearnModels.jl)
+[![][build-img]][build-url] [![][codecov-img]][codecov-url]
 
-Statistical learning models for tabular data.
+Statistical learning models for [Tables.jl](https://github.com/JuliaData/Tables.jl) tables.
+
+## Installation
+
+Get the latest stable release with Julia's package manager:
+
+```
+] add StatsLearnModels
+```
+
+## Usage
+
+This package provides a `Learn` transform that implements the
+[TableTransforms.jl](https://github.com/JuliaML/TableTransforms.jl)
+interface.
+
+Given two [Tables.jl](https://github.com/JuliaData/Tables.jl)
+tables with training and test data:
+
+```julia
+train = (feature1=rand(100), feature2=rand(100), target=rand(1:2, 100))
+test = (feature1=rand(20), feature2=rand(20))
+```
+
+One can train a learning `model` (e.g. `RandomForestClassifier`) with
+the `train` table:
+
+```julia
+model = RandomForestClassifier()
+
+learn = Learn(train, model, ["feature1","feature2"] => "target")
+```
+
+and apply the trained `model` to the `test` table:
+
+```julia
+pred = learn(test)
+```
+
+The package exports native Julia models from various packages
+in the ecosystem. It is also possible to use models from the
+[MLJ.jl](https://github.com/JuliaAI/MLJ.jl) stack.
+
+The combination of TableTransforms.jl with StatsLearnModels.jl
+can be thought of as a powerful alternative to MLJ.jl.
+
+[build-img]: https://img.shields.io/github/actions/workflow/status/JuliaML/StatsLearnModels.jl/CI.yml?branch=master&style=flat-square
+[build-url]: https://github.com/JuliaML/StatsLearnModels.jl/actions
+
+[codecov-img]: https://img.shields.io/codecov/c/github/JuliaML/StatsLearnModels.jl?style=flat-square
+[codecov-url]: https://codecov.io/gh/JuliaML/StatsLearnModels.jl