add packery, filter menu

Signed-off-by: Erica <e@energy7.com>
replace packery w/isotope, make dropdown menus for filters

packery doesn't have filters, it's intended more for drag and drop layouts. it will be a layout mode in isotope eventually, according to the docs.

Signed-off-by: Erica <e@energy7.com>
tweak menu style

Signed-off-by: Erica <e@energy7.com>
swap margin/padding

Signed-off-by: Erica <e@energy7.com>
delete packery js

Signed-off-by: Erica <e@energy7.com>