Small work on ReadMe.adoc

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pastecs@17 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Further rework of ReadMe.adoc

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pastecs@18 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Typo correction in ReadMe.adoc

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pastecs@19 edb9625f-4e0d-4859-8d74-9fd3b1da38cb