Added more documentation.

README.md

@@ -5,12 +5,14 @@ snaphots of ZFS datasets (pools, filsystems) according to a set of
 configurable schedules. Options for interval and crontab-style
 schedules are available.
 
-The daemon only includes an installer for macOS at the moment,
+The daemon includes an installer for macOS `launchd`. For Linux,
-but a multi-platform installer is coming soon.
+see the example `systemd` config file in `docs`. Modify as needed,
+copy to `/etc/systemd/system` folder, run `systemctl start zasd`
+and `systemctl enable zasd` as root to run on boot.
 
-As of now, snapshots are conditional. A snapshot will only be taken
+Snapshots may be made conditional with the `if_modified` option
-if a dataset has been modified since the last snapshot. An option
+on each schedule. In this mode, a snapshot will only be taken if
-to turn this off per schedule is coming soon.
+a dataset has been modified since the last snapshot.
 
 The daemon should not interfere with other snapshots you have
 on the system, unless you give them names that adhere to the

docs/zasd.example.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=ZFS Automatic Snapshot Daemon
+
+[Service]
+User=root
+WorkingDirectory=/root/zasd/src
+ExecStart=/usr/bin/python3 zasd.py
+Restart=always
+SyslogIdentifier=zasd
+
+[Install]
+WantedBy=multi-user.target