Add menu to index.html
Remove old frame styles

Delete old, obsolete frame-related sass files and styles and replace
them with a new file for menu styles.
Change default font size to 16px
Add light grey color
Add dotted border-bottom
Position things
Add variables for font size and weight

Add variables for three different font sizes as well as a variable for
the semi-bold font-weight. Set font-size and font-weight of top-menu.
Finish top menu
Dropdown carets and filter-menu positioning