[cvs-nhc98] Documentation: split off a new "Language extensions" page

malcolm: Tue Oct 23 19:11:55 CEST 2001 Update of /usr/src/master/nhc/docs In directory hinken:/tmp/cvs-serv6276 Modified Files: york-release.html index.html Added Files: extensions.html Log Message: Documentation: split off a new "Language extensions" page from the current "Why use nhc98?" page.