Improve README.

README.md

@@ -5,21 +5,17 @@ Base functionality for optimization and solving systems of equations in Julia.
 
 NLSolversBase.jl is the core, common dependency of several packages in the [JuliaNLSolvers](https://julianlsolvers.github.io) family.
 
-The package aims at establishing common ground for [Optim.jl](https://github.com/JuliaNLSolvers/Optim.jl) and [LineSearches.jl](https://github.com/JuliaNLSolvers/LineSearches.jl), but [NLsolve.jl](https://github.com/JuliaNLSolvers/NLsolve.jl) will eventually also depend on this package. The common ground is mainly the types used to hold objectives and information about the objectives, and an interface to interact with these types.
-
-Travis-CI
 
-[![Build Status](https://travis-ci.org/JuliaNLSolvers/NLSolversBase.jl.svg?branch=master)](https://travis-ci.org/JuliaNLSolvers/NLSolversBase.jl)
+| **PackageEvaluator**            |**Build Status**                                   |
+|:-------------------------------:|:-------------------------------------------------:|
+| [![][pkg-0.4-img]][pkg-0.4-url] | [![Build Status][build-img]][build-url]           |
+| [![][pkg-0.5-img]][pkg-0.5-url] | [![Codecov branch][cov-img]][cov-url]             |
+| [![][pkg-0.6-img]][pkg-0.6-url] | [![Coverage Status][coveralls-img]][coveralls-url] |
 
-Package evaluator
 
-[![pkg-0.4-img](http://pkg.julialang.org/badges/NLSolversBase_0.5.svg)](http://pkg.julialang.org/?pkg=NLSolversBase&ver=0.5)
-[![pkg-0.4-img](http://pkg.julialang.org/badges/NLSolversBase_0.6.svg)](http://pkg.julialang.org/?pkg=NLSolversBase&ver=0.6)
+# Purpose
 
-Code coverage
-
-[![Coverage Status](https://coveralls.io/repos/JuliaNLSolvers/NLSolversBase.jl/badge.svg?branch=master&service=github)](https://coveralls.io/github/JuliaNLSolvers/NLSolversBase.jl?branch=master)
-[![codecov.io](http://codecov.io/github/JuliaNLSolvers/NLSolversBase.jl/coverage.svg?branch=master)](http://codecov.io/github/pkofod/NLSolversBase.jl?branch=master)
+The package aims at establishing common ground for [Optim.jl](https://github.com/JuliaNLSolvers/Optim.jl) and [LineSearches.jl](https://github.com/JuliaNLSolvers/LineSearches.jl), but [NLsolve.jl](https://github.com/JuliaNLSolvers/NLsolve.jl) will eventually also depend on this package. The common ground is mainly the types used to hold objectives and information about the objectives, and an interface to interact with these types.
 
 # What
 This package holds types for use in the JuliaNLSolvers family of packages. The types act as collections of callables relevant for optimization or solution of systems of equations (objective, (partial) derivatives of different orders), and cache variables needed to evaluate their values.
@@ -100,3 +96,19 @@ nd   = NonDifferentiable(f!, x, F)
 od   = OnceDifferentiable(f!, j!, x, F)
 odfj = OnceDifferentiable(f!, j!, fj! x, F)
 ```
+
+[build-img]: https://travis-ci.org/JuliaNLSolvers/NLSolversBase.jl.svg?branch=master
+[build-url]: https://travis-ci.org/JuliaNLSolvers/NLSolversBase.jl
+
+[pkg-0.4-img]: http://pkg.julialang.org/badges/NLSolversBase_0.4.svg
+[pkg-0.4-url]: http://pkg.julialang.org/?pkg=NLSolversBase&ver=0.4
+[pkg-0.5-img]: http://pkg.julialang.org/badges/NLSolversBase_0.5.svg
+[pkg-0.5-url]: http://pkg.julialang.org/?pkg=NLSolversBase&ver=0.5
+[pkg-0.6-img]: http://pkg.julialang.org/badges/NLSolversBase_0.6.svg
+[pkg-0.6-url]: http://pkg.julialang.org/?pkg=NLSolversBase&ver=0.6
+
+[cov-img]: http://codecov.io/github/JuliaNLSolvers/NLSolversBase.jl/coverage.svg?branch=master
+[cov-url]: http://codecov.io/github/pkofod/NLSolversBase.jl?branch=master
+
+[coveralls-img]: https://coveralls.io/repos/JuliaNLSolvers/NLSolversBase.jl/badge.svg?branch=master&service=github
+[coveralls-url]: https://coveralls.io/github/JuliaNLSolvers/NLSolversBase.jl?branch=master