Examine source code of Display None

{
  "manifest_version": 2,
  "name": "Display None",
  "version": "1.1resigned1",
  "author": "Charles-Elie Pidancet",
  "homepage_url": "https://github.com/Cethy/webextension-displaynone",
  "description": "Add a context action to hide element from a webPage (and a second one to reset all modifications).",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contextAction-helper.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{91c7062d-e918-42da-a78b-36032f34b037}"
    }
  }
}