Added three great R books (#2170)

* Added three great R books

* Fixed entries

removed the potentially not free book, and alphabetized entries

* Update free-programming-books.md

free-programming-books.md

@@ -1889,19 +1889,22 @@ For resources on Angular, Backbone, D3, Dojo, Ember, Express, jQuery, Knockout,
 ### R
 
 * [Advanced R Programming](http://adv-r.had.co.nz) - Hadley Wickham
+* [Cookbook for R](http://www.cookbook-r.com) - Winston Chang
 * [Introduction to Probability and Statistics Using R](http://cran.r-project.org/web/packages/IPSUR/vignettes/IPSUR.pdf) - G. Jay Kerns (PDF)
-* [Learning Statistics with R](http://health.adelaide.edu.au/psychology/ccs/teaching/lsr/) - Daniel Navarro
+* [Learning Statistics with R](http://health.adelaide.edu.au/psychology/ccs/teaching/lsr) - Daniel Navarro
 * [learnR](https://github.com/yuanlisky/learnR) - (Work in Progress) - Kun Ren
 * [Practical Regression and Anova using R](http://cran.r-project.org/doc/contrib/Faraway-PRA.pdf) - Julian J. Faraway (PDF)
-* [R for spatial analysis](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/spatialEpiBook.pdf) (PDF)
-* [R language for Programmers](http://www.johndcook.com/blog/r_language_for_programmers/) - John D. Cook
-* [R packages](http://r-pkgs.had.co.nz) - Hadley Wickham
-* [R practicals](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/R/practicalsBookNoAns.pdf) (PDF)
+* [R for Data Science](http://r4ds.had.co.nz) - Garrett Grolemund and Hadley Wickham
+* [R for Spatial Analysis](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/spatialEpiBook.pdf) (PDF)
+* [R Language for Programmers](http://www.johndcook.com/blog/r_language_for_programmers) - John D. Cook
+* [R Packages](http://r-pkgs.had.co.nz) - Hadley Wickham
+* [R Practicals](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/R/practicalsBookNoAns.pdf) (PDF)
 * [R Programming](https://en.wikibooks.org/wiki/R_Programming)
 * [R Programming for Data Science](https://leanpub.com/rprogramming) (Needs valid email)
 * [R Succinctly, Syncfusion](https://www.syncfusion.com/resources/techportal/ebooks/rsuccinctly) (PDF, Kindle) *(Just fill the fields with any values)*
+* [The caret Package](http://topepo.github.io/caret/index.html) - Max Kuhn
 * [The R Inferno](http://www.burns-stat.com/pages/Tutor/R_inferno.pdf) - Patrick Burns (PDF)
-* [The R Language](http://stat.ethz.ch/R-manual/R-patched/doc/html/)
+* [The R Language](http://stat.ethz.ch/R-manual/R-patched/doc/html)
 * [The R Manuals](http://cran.r-project.org/manuals.html)