Update number_translations.rst (#116)

Added information as how to enable the module and enable number translation in a SIP-profile.

source/advanced/number_translations.rst

@@ -9,5 +9,13 @@ Use this to translate numbers from the original number to a new number using reg
 .. image:: ../_static/images/advanced/fusionpbx_advanced_number_translations.jpg
         :scale: 85%
 
+Activating mod-translate:
+1. Install the package "freeswitch-mod-translate" via aptitude/apt-get etc.
+2. Configure the module to your likes via the GUI: Advanced -> Number Translations. 
+3. Activate the module in FusionPBX Advanced -> Modules in the Applications section
 
+The documentation for mod-translate can be found under https://freeswitch.org/confluence/display/FREESWITCH/mod_translate
 
+To use mod-translate to modify inbound calls before they hit the dialplan the following setting for the SIP-profile must be modified:
+  dialplan "XML" -> dialplan "Translate,XML"
+To activate this setting, the SIP-profile needs to be restarted and memcache flushed.