add readme

Author: ablaom

README.md

@@ -0,0 +1,43 @@
+# MLJOpenML.jl
+
+| Linux | Coverage |
+| :-----------: | :------: |
+| [![Build status](https://github.com/JuliaAI/MLJOpenML.jl/workflows/CI/badge.svg)](https://github.com/JuliaAI/MLJOpenML.jl/actions)| [![codecov.io](http://codecov.io/github/JuliaAI/MLJOpenML.jl/coverage.svg?branch=master)](http://codecov.io/github/JuliaAI/MLJOpenML.jl?branch=master) |
+
+A package providing integration of [OpenML](https://www.openml.org) with the
+[MLJ](https://alan-turing-institute.github.io/MLJ.jl/dev/) machine
+learning framework.
+
+
+## Installation
+
+```julia
+using Pkg
+Pkg.add("MLJOpenML")
+```
+
+## Sample usage
+
+Load the iris data set from OpenML:
+
+```julia
+using MLJOpenML
+rowtable = MLJOpenML.load(61)
+```
+
+Convert to a `DataFrame`:
+
+```
+Pkg.add("DataFrames")
+using DataFrames
+df = DataFrame(rowtable)
+```
+
+## Documentation
+
+Documentation is provided in the [OpenML
+Integration](https://alan-turing-institute.github.io/MLJ.jl/dev/openml_integration/)
+section of the
+[MLJManual](https://alan-turing-institute.github.io/MLJ.jl/dev/)
+
+

src/openml.jl

@@ -100,6 +100,8 @@ example:
 using DataFrames
 rowtable = MLJOpenML.load(61);
 df = DataFrame(rowtable);
+
+using MLJ
 df2 = coerce(df, :class=>Multiclass)
 ```
 """