Added css and index files.
Made js file, added data state

Added date state inactive to both of the asides. Made javascript file.
Added displays to sales__details in css.

Added display none to sales__details. Added another sales details in
css with data state active. Put display block in this. In js, added
variables for sales and sales__details.
Changed the classes, edited the js.

Added classes sales1 & 2, sales__details1 & 2. edited the js so that
these classes were used.