Update README.md

Author: davidanthoff

README.md

@@ -4,3 +4,5 @@
 [![Build Status](https://travis-ci.org/queryverse/QuerySQLite.jl.svg?branch=master)](https://travis-ci.org/queryverse/QuerySQLite.jl)
 [![Build status](https://ci.appveyor.com/api/projects/status/vluand1dj4x7i3iy/branch/master?svg=true)](https://ci.appveyor.com/project/queryverse/querysqlite-jl/branch/master)
 [![codecov.io](http://codecov.io/github/queryverse/QuerySQLite.jl/coverage.svg?branch=master)](http://codecov.io/github/queryverse/QuerySQLite.jl?branch=master)
+
+This package provides a SQLite backend for [Query.jl](https://github.com/queryverse/Query.jl).