This mentions needing to enable ACLs on the file-system, and adds the
packages that need to be installed.
Closes #12.
Note: to build from source, by default, Python 3 is needed. It can
still be built with Python 2, by calling `make PYTHON=python2`.
+FreeBSD
++++++++
+
+Note that on FreeBSD, ACLs are not enabled by default (at least on UFS
+file systems). To enable them, run `tunefs -a enabled` on the file
+system in question (after mounting it read-only). Then install:
+
+- pkg install py36-setuptools py36-sphinx
+
+or:
+
+- pkg install py37-setuptools
+
License
-------