Examine source code of Cognitive Comfort

{
  "manifest_version": 2,
  "name": "Cognitive Comfort",
  "description": "Hide distracting media until you intentionally reveal it.",
  "version": "0.3.0",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "96": "icon-96.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "commands": {
    "toggle-pause": {
      "suggested_key": {
        "default": "Ctrl+Shift+U",
        "mac": "MacCtrl+Shift+U"
      },
      "description": "Pause or resume Cognitive Comfort"
    },
    "toggle-site": {
      "suggested_key": {
        "default": "Ctrl+Shift+O",
        "mac": "MacCtrl+Shift+O"
      },
      "description": "Toggle Cognitive Comfort for the current site"
    },
    "peek-show": {
      "suggested_key": {
        "default": "Ctrl+Shift+A",
        "mac": "MacCtrl+Shift+A"
      },
      "description": "Peek: briefly reveal hidden media"
    },
    "toggle-global": {
      "suggested_key": {
        "default": "Ctrl+Shift+E",
        "mac": "MacCtrl+Shift+E"
      },
      "description": "Show or hide media on every site"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "cognitive-comfort@olegpulatov.github.io",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Cognitive Comfort",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/comfort.js"
      ]
    }
  ]
}