updated README description

README.md

@@ -1 +1,9 @@
-**bash script for either changing HDD drives spindown time or checking if it is spinning or not**
+**bash script for either telling all HDDs in system to spindown or checking if it is spinning or not**
+*Prerequisites*:
+    - sudo apt install hdparm
+    - drives are listed as /dev/sdX where X stands for their respective labeling for the system
+
+**Usage**:
+    $ ./HDD.sh (1/2)
+    - option 1) tell drives to spindown
+    - option 2) check if drives are spinning or not