fix possessive
Initialisation
==============
-Before running Routinator for the first time, you must prepare its working
+Before running Routinator for the first time, you must prepare the working
environment. You do this using the :subcmd:`init` subcommand. This will prepare
both the directory for the local RPKI cache, as well as the directory where the
Trust Anchor Locator (TAL) files reside.
