Configure package exports explicitly (#336)

Closes #337
Blocks https://github.com/webrecorder/archiveweb.page/issues/198

Adds a dedicated `misc` export, as well as explicitly exporting the
`electron-*` files and the `index.html` file. This restricts imports to
only these files, and allows us to not have to exactly match webpack
configs between RWP and AWP.

tsconfig.json

@@ -3,7 +3,7 @@
     "outDir": "./dist/",
     "module": "esnext",
     "target": "es6",
-    "moduleResolution": "node",
+    "moduleResolution": "Bundler",
     "allowJs": true,
     "strict": true,
     "declaration": true,