install.sh: correct typo in variable definition

install.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 run_directory=$(dirname "$0")
-$user=$(whoami)
+user=$(whoami)
 
 echo "Copying bashrc-ffarchiving to extensions directory..."
 cp $run_directory/templates/bashrc-ffarchiving /home/$user/.bashrc.d/