Improve image sizes

assets/images/amoled@220.png

assets/images/amoled@266.png

assets/images/amoled@335.png

assets/images/amoled@352.png

assets/images/amoled@532.png

assets/images/generate_assets.sh

assets/images/gruvbox_dark@220.png

assets/images/gruvbox_dark@266.png

assets/images/gruvbox_dark@335.png

assets/images/gruvbox_dark@352.png

assets/images/gruvbox_dark@532.png

assets/images/gruvbox_light@220.png

assets/images/gruvbox_light@266.png

assets/images/gruvbox_light@335.png

assets/images/gruvbox_light@352.png

assets/images/gruvbox_light@532.png

assets/images/phone@1000.png

assets/images/phone@1220.png

assets/images/phone@220.png

assets/images/phone@300.png