Examine source code of Hide Youtube Useless

{
  "manifest_version": 2,
  "name": "Hide Youtube Useless",
  "version": "1.0",
  "description": "Cache les boutons inutiles de youtube",
  "homepage_url": "https://github.com/Tenteur592/HideYoutubeUseless",
  "icons": {
    "48": "icons/useless.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "hideUseless.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/useless.png",
    "default_title": "Hide Youtube Useless",
    "default_popup": "popup/popup.html"
  },
  "web_accessible_resources": [
    "files/properties.json"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{665c14a1-6288-4e3e-8d29-dc0d1c62c65b}"
    }
  }
}