frontend aesthetics; need to implement deleting collections

...summarization-frontend/public/images/canada_wildfires.jpg

...vents-text-summarization-frontend/public/images/covid.png

...ization-frontend/public/images/monterey_park_shooting.jpg

...end/crisis-events-text-summarization-frontend/src/App.css

...tend/crisis-events-text-summarization-frontend/src/App.js

...end/crisis-events-text-summarization-frontend/src/Home.js

...crisis-events-text-summarization-frontend/src/Sidebar.css

...ents-text-summarization-frontend/src/collection_editor.js

...events-text-summarization-frontend/src/collection_list.js