ess: add description, features to readme

layers/+lang/ess/README.org

@@ -3,12 +3,23 @@
 [[file:img/r.jpg]]
 
 * Table of Contents                                         :TOC_4_gh:noexport:
+- [[#description][Description]]
+  - [[#features][Features:]]
 - [[#install][Install]]
 - [[#key-bindings][Key Bindings]]
   - [[#inferior-repl-process][Inferior REPL process]]
   - [[#helpers][Helpers]]
 - [[#options][Options]]
 
+* Description
+This layer adds support for statistical analysis through [[https://ess.r-project.org/][ESS]].
+
+** Features:
+- All [[https://ess.r-project.org/Manual/ess.html#Current-Features][ESS features]]
+- Additional data viewer for R via [[https://github.com/myuhe/ess-R-data-view.el][ess-R-data-view]]
+- Support for Org-Babel
+- Better 'equals' behavior via [[https://github.com/genovese/ess-smart-equals][ess-smart-equals]]
+
 * Install
 To use this configuration layer, add it to your =~/.spacemacs=. You will need to
 add =ess= to the existing =dotspacemacs-configuration-layers= list in this