Examine source code of yt0s

{
  "manifest_version": 2,
  "name": "yt0s",
  "description": "YouTube right-click option to start at 0:00 seconds",
  "version": "1.6",
  "homepage_url": "https://github.com/sahlaysta",
  "icons": {
    "48": "icons/yt0s-48.png"
  },
  "permissions": [
    "contextMenus"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "yt0s_runtime_api.js",
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "yt0s_runtime_api.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{aac21efe-7584-4819-962f-b10ec8ac77f9}"
    }
  }
}