Examine source code of PDF.js with VimiumC

{
  "manifest_version": 2,
  "name": "PDF.js with VimiumC",
  "version": "1.0",
  "description": "Replace Firefox's built-in PDF viewer with a custom PDF.js build.",
  "applications": {
    "gecko": {
      "id": "sxlxcsxlxc@gmail.com"
    }
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "viewer.html",
    "viewer.mjs",
    "viewer.mjs.map",
    "viewer.css",
    "viewer-boot.js",
    "cmaps/*",
    "iccs/*",
    "images/*",
    "locale/*",
    "standard_fonts/*",
    "wasm/*",
    "build/*",
    "inject-vimc.js"
  ]
}