Examine source code of Flight to Calendar

{
  "manifest_version": 2,
  "name": "Flight to Calendar",
  "version": "1.1",
  "description": "Download flight details as ICS calendar file (EasyJet, TAP Portugal, Vueling, LATAM)",
  "browser_specific_settings": {
    "gecko": {
      "id": "flight-to-calendar@jsantos.me",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "icons": {
    "48": "icons/icon-48.svg",
    "96": "icons/icon-96.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48-disabled.svg",
      "96": "icons/icon-96-disabled.svg"
    },
    "default_title": "Download Flight ICS",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.easyjet.com/*"
      ],
      "js": [
        "timezones.js",
        "content-easyjet.js"
      ]
    },
    {
      "matches": [
        "*://*.flytap.com/*"
      ],
      "js": [
        "timezones.js",
        "content-tap.js"
      ]
    },
    {
      "matches": [
        "*://*.vueling.com/*"
      ],
      "js": [
        "timezones.js",
        "content-vueling.js"
      ]
    },
    {
      "matches": [
        "*://*.latamairlines.com/*"
      ],
      "js": [
        "timezones.js",
        "content-latam.js"
      ]
    }
  ]
}