Merge branch 'activity_feed' of github.com:metabase/metabase-init into activity_feed

...ontend_client/app/components/icons/assets/header_rect.svg

resources/frontend_client/app/css/core/hide.css

resources/frontend_client/app/css/core/layout.css

resources/frontend_client/app/css/home.css

...ces/frontend_client/app/home/components/Activity.react.js

...frontend_client/app/home/components/ActivityItem.react.js

...rontend_client/app/home/components/ActivityStory.react.js

resources/frontend_client/app/home/components/Cards.react.js

...s/frontend_client/app/home/components/HeaderTabs.react.js

...ces/frontend_client/app/home/components/Homepage.react.js

resources/frontend_client/index_template.html