Update README.md

Author: amirali-dashti

README.md

@@ -28,6 +28,16 @@ functions:
              unused packages. Does not accept <input>, but has 
              a confirmation prompt.
 
+    backup:  Creates a backup of all installed packages' names. Does not
+             accept <input>, but includes a confirmation prompt.
+             You can choose the location of the backup file or use the
+             default location generated by the script.
+
+    recover: Recovers packages from a backup file. Reads each line
+             of the file and installs the packages listed. Accepts the
+             backup file as <input>. Includes a confirmation prompt.
+             You can choose to run an update and a cleaup afterwards.
+
 flags: 
     --help/-h: Display this page