Examine source code of Linefeed

{
  "manifest_version": 2,
  "name": "__MSG_extension_name__",
  "description": "__MSG_extension_description__",
  "version": "0.0.10.9",
  "author": "Codifier",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "{b1287793-f632-47b2-815f-a8fd43074802}",
      "strict_min_version": "63.0"
    }
  },
  "background": {
    "scripts": [
      "/assets/js/constants.js",
      "/assets/js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "/assets/js/util.js",
        "/assets/js/constants.js",
        "/assets/components/Linefeed/js/FeedParser.js",
        "/assets/components/Linefeed/js/FeedDiscoverer.js",
        "/assets/js/content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "browser_style": false,
    "default_title": "__MSG_extension_name__",
    "default_icon": {
      "12": "/assets/img/icon-12.png",
      "16": "/assets/img/icon-16.png",
      "19": "/assets/img/icon-19.png",
      "32": "/assets/img/icon-32.png",
      "38": "/assets/img/icon-38.png",
      "48": "/assets/img/icon-48.png",
      "64": "/assets/img/icon-64.png",
      "80": "/assets/img/icon-80.png",
      "96": "/assets/img/icon-96.png",
      "112": "/assets/img/icon-112.png",
      "128": "/assets/img/icon-128.png",
      "256": "/assets/img/icon-256.png",
      "512": "/assets/img/icon-512.png"
    }
  },
  "icons": {
    "12": "/assets/img/icon-12.png",
    "16": "/assets/img/icon-16.png",
    "19": "/assets/img/icon-19.png",
    "32": "/assets/img/icon-32.png",
    "38": "/assets/img/icon-38.png",
    "48": "/assets/img/icon-48.png",
    "64": "/assets/img/icon-64.png",
    "80": "/assets/img/icon-80.png",
    "96": "/assets/img/icon-96.png",
    "112": "/assets/img/icon-112.png",
    "128": "/assets/img/icon-128.png",
    "256": "/assets/img/icon-256.png",
    "512": "/assets/img/icon-512.png"
  },
  "commands": {
    "add-feed": {
      "suggested_key": {
        "default": "Ctrl+Insert"
      },
      "description": "__MSG_command_add_feed__"
    },
    "add-tab": {
      "suggested_key": {
        "default": "Ctrl+Shift+Insert"
      },
      "description": "__MSG_command_add_tab__"
    }
  },
  "permissions": [
    "tabs",
    "storage",
    "unlimitedStorage",
    "downloads",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ]
}