[mkgmap-dev] Commit r4283: document special case with relative path for option input-file given in a config file like template.args

Version mkgmap-r4283 was committed by gerd on Fri, 08 Mar 2019 document special case with relative path for option input-file given in a config file like template.args http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4283