docs: add hdparm quick reference

cli/hdparm.md

@@ -0,0 +1,22 @@
+
+enable power save
+```
+hdparm -B 127 /dev/sdX
+```
+
+set spindown time to 20min (1-240) x 5sec
+```
+hdparm -S 240 /dev/sdX
+```
+
+check current state
+```
+hdparm -C /dev/sdX
+```
+
+to persistent configuration across reboot using udev rule, please put the following content to `/etc/udev/rules.d/69-hdparm.rules`
+```
+ACTION=="add|change", KERNEL=="sd[a-z]", ATTRS{queue/rotational}=="1", RUN+="/usr/bin/hdparm -B 127 -S 240 /dev/%k"
+```
+
+for more detail: https://wiki.archlinux.org/title/hdparm