Examine source code of Element Remover

{
  "manifest_version": 2,
  "name": "Element Remover",
  "version": "1.0",
  "description": "Remove the unwanted parts of a web page with a simple right-click",
  "homepage_url": "https://gitlab.com/mit-open-source-projects/firefox-extensions/element-remover",
  "icons": {
    "48": "icons/remover-48.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "page_action": {
    "default_icon": "icons/remover-32.png",
    "default_title": "Element Remover"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "element-remover.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}