Make systemd service file more robust

Signed-off-by: Ethan Dye <mrtops03@gmail.com>

README.md

@@ -45,6 +45,7 @@ Experimental Alpine support has also been added, other distributions may work bu
 ``` shell
 sudo apt-get install git
 git clone --recurse-submodules https://github.com/ecdye/zram-config
+cd zram-config
 sudo ./zram-config/install.bash
 ```
 

service/SystemD/zram-config.service

@@ -1,11 +1,21 @@
 [Unit]
 Description=zram-config
 Documentation=https://github.com/ecdye/zram-config/blob/main/README.md
+DefaultDependencies=no
+Before=basic.target rsyslog.service syslog-ng.service syslog.target systemd-journald.service sysinit.target shutdown.target
+Conflicts=shutdown.target reboot.target halt.target
+RequiresMountsFor=/var/log /opt/zram
+IgnoreOnIsolate=yes
+After=local-fs.target
 
 [Service]
-Type=exec
+Type=oneshot
 WorkingDirectory=/usr/local/lib/zram-config
 ExecStart=/usr/local/sbin/zram-config "start"
+ExecReload=/usr/local/sbin/zram-config "sync"
+ExecStop=/usr/local/sbin/zram-config "stop"
+TimeoutStopSec=120
+RemainAfterExit=yes
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=sysinit.target