Add safety section to RF Chamber

[GeorgesOatesLarsen]

Notes by Haneef:
Not really an SOP, more like a services offered page.
Makes sense.
If we want an SOP, we should probably also talk about Chamber safety to prevent equipment damage.

http://psu-epl.github.io/doc/equip/testing/RF-Chamber

To resolve this issue, add safety information to the RF chamber page.