fix formatting of link in README.md

Author: ablaom

README.md

@@ -37,7 +37,7 @@ support such algorithms.
 
 - [StatisticalMeasures.jl](https://github.com/JuliaAI/StatisticalMeasures.jl): Package providing metrics, compatible with LearnAPI.jl
 
-- [StatsModels.jl](https://github.com/JuliaStats/StatsModels.jl): Provides the R-style formula implementation of data preprocessing handled by [LearnDataFrontEnds.jl]((https://github.com/JuliaAI/LearnDataFrontEnds.jl)
+- [StatsModels.jl](https://github.com/JuliaStats/StatsModels.jl): Provides the R-style formula implementation of data preprocessing handled by [LearnDataFrontEnds.jl](https://github.com/JuliaAI/LearnDataFrontEnds.jl)
 
 ### Selected packages providing alternative API's