Examine source code of Add to Dropmark

{
  "manifest_version": 2,
  "version": "2.0.2.1",
  "name": "Add to Dropmark",
  "description": "A quick way to add links, images, and screenshots to your Dropmark collections.",
  "applications": {
    "gecko": {
      "id": "extension@dropmark.com",
      "strict_min_version": "48.0"
    }
  },
  "background": {
    "scripts": [
      "assets/js/background.min.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "/assets/js/content-script.min.js"
      ]
    }
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "browser_action": {
    "default_icon": {
      "16": "/assets/images/icon-16.png",
      "32": "/assets/images/icon-16@2x.png"
    },
    "theme_icons": [
      {
        "light": "/assets/images/icon-16-light.svg",
        "dark": "/assets/images/icon-16-dark.svg",
        "size": 16
      },
      {
        "light": "/assets/images/icon-16-light.svg",
        "dark": "/assets/images/icon-16-dark.svg",
        "size": 32
      }
    ],
    "default_popup": "/views/popup.html",
    "default_title": "Add to Dropmark"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+Shift+D"
      }
    }
  },
  "permissions": [
    "<all_urls>",
    "contextMenus",
    "storage",
    "tabs"
  ],
  "icons": {
    "16": "assets/images/icon-16.png",
    "32": "assets/images/icon-32.png",
    "48": "assets/images/icon-48.png",
    "64": "assets/images/icon-64.png",
    "128": "assets/images/icon-128.png"
  },
  "options_ui": {
    "page": "/views/options/options.html",
    "chrome_style": true
  }
}