[Fiware-tech-help] [Chp - IoT][IDAS] Redundant and incomplete monit install information

[David Muriel]

The installation guide has instruction to install monit on several of
the sections, as this is a requirement for most of them.  This
information is repeated on different sections and some of them is
incomplete.  As this is used by several components of the platform, it
is better to add the needed information in one place of the document
and then add references to it on the appropiate sections when needed.