Reorder, fix typo

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tm@1350 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Link to high-level corpus description

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tm@1351 edb9625f-4e0d-4859-8d74-9fd3b1da38cb