Added .f-list.menu and removed overriding margin in .f-list

Take a look at the demo page for the `.f-list.menu` class. If we add `.f-clickable` to it, it'll add a box-shadow set on `li:active` click. This is used on the new mobile pages to navigate to the fundraisers/teams pages.

As for the overriding margin commit, adding a `.f-m*` class to the `.f-list` does nothing. It seems to be like a bug to me so I changed it. LMK if this expected behavior, I'll just wrap my `.f-list` w/ a div containing the margins.