Make outdated install guide refer to the wiki instead (#2431).

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21779 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2542 Added descriptions of .dat file outputs to cell writers

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@21780 b5f69653-2bf5-0310-8201-b0dafb8e1405