Add manifest fields for PWA install bottom sheet (#933)

* Add manifest fields for PWA install bottom sheet

* Switch to webp

* Revert "Switch to webp"

This reverts commit c60d0d9629.

* Try JPEG

* Use mime-type library

* Automate image size

Co-authored-by: Jake Archibald <jaffathecake@gmail.com>

package.json

@@ -16,6 +16,7 @@
     "@rollup/plugin-replace": "^2.3.4",
     "@surma/rollup-plugin-off-main-thread": "^1.4.2",
     "@types/dedent": "^0.7.0",
+    "@types/mime-types": "^2.1.0",
     "@types/node": "^14.14.7",
     "comlink": "^4.3.0",
     "cssnano": "^4.1.10",
@@ -24,10 +25,11 @@
     "file-drop-element": "^1.0.1",
     "husky": "^4.3.0",
     "idb-keyval": "^3.2.0",
+    "image-size": "^0.9.3",
     "linkstate": "^2.0.0",
     "lint-staged": "^10.5.1",
     "lodash.camelcase": "^4.3.0",
-    "mime-types": "^2.1.27",
+    "mime-types": "^2.1.28",
     "npm-run-all": "^4.1.5",
     "pointer-tracker": "^2.4.0",
     "postcss": "^7.0.35",