Managed repository template path expansions

Documents managed repository template path expansion terms, accompanying https://github.com/openmicroscopy/openmicroscopy/pull/2701. These changes are staged at http://www.openmicroscopy.org/site/support/omero5-staging/sysadmins/fs-upload-configuration.html.
Did not get the meaning of the sentence, because of the opaqueness of the ``component`` meaning. I understand now this is the part of the path between any two slashes, but this is only very much post-hoc and with explanation from @mtbc