Compile sass command line executable

 #compiles a single file manually.
 node-sass my-styles.scss my-styles.css 
 #compiles all the files in a folder manually.
 node-sass my-sass-folder/ -o my-css-folder/
 # compiles all the files in a folder automatically 
 #whenever the source file(s) are modified. -w adds 
 #a watch for changes to the file(s).
 node-sass -w sass/ -o css/