Updated Default port allocations (markdown)
Added Github Exporter to port mappings page.
Add s6_exporter
Added Docker Hub Exporter
Reserving port 9162 for apcupsd_exporter
Add Sonatype Nexus exporter
Removed broken link
Added Openstack exporter port. This is different from "Openstack Ceilometer exporter" as it will not use ceilometer
Fix instances of 'cloud' replace by 'butt'
Adding scyllaDB default port exporter
Reserving portnumber for IBM MQ exporter
Updated HOWTO cut a new release (markdown)