Added comment which two packages are needed on FreeBSD.

docsite/latest/rst/playbooks_acceleration.rst

@@ -19,6 +19,7 @@ Accelerated mode offers several improvments over the original fireball mode:
 * No bootstrapping is required, only a single line needs to be added to each play you wish to run in accelerated mode.
 * Support for sudo commands (see below for more details and caveats).
 * Fewer requirements! ZeroMQ is no longer required, nor are there any special packages beyond python-keyczar.
+* On FreeBSD you will need security/py-keyczar and devel/py-asn1.
 
 In order to use accelerated mode, simply add `accelerate: true` to your play::
 
@@ -117,4 +118,3 @@ any platform.  You will also need gcc and zeromq-devel installed from your packa
 Fedora and EPEL also have Ansible RPM subpackages available for fireball-dependencies.
 
 Also see the module documentation section.
-