filter function, css link etc

[lucymk]

• linked in css and added a TINY bit of style so that tags were more clickable
• made a new resultAdd.hbs page as they weren't rendering after clicking 'add' due to different naming
• tried to fix broken tests but keep getting same error: (node:93884) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 7): TypeError: Cannot read property 'catch' of undefined

😭