Examine source code of Search7

{
  "manifest_version": 2,
  "name": "Search7",
  "version": "0.2.0",
  "description": "A Web Search Tool",
  "icons": {
    "64": "asset/icon64.png",
    "128": "asset/icon128.png",
    "256": "asset/icon256.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "54.0a1",
      "id": "{2fb9db1f-4098-42da-8a72-672e00c1ead3}"
    }
  },
  "browser_action": {
    "default_title": "Search7",
    "default_icon": "asset/icon.svg"
  },
  "sidebar_action": {
    "default_title": "Search7",
    "default_icon": "asset/icon.svg",
    "default_panel": "sidepanel.html"
  },
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+7"
      }
    }
  },
  "permissions": [
    "tabs",
    "storage",
    "*://www.google.com/search?q=*",
    "*://suggestqueries.google.com/complete/search?output=toolbar&q=*",
    "*://html.duckduckgo.com/html/?q=*",
    "*://duckduckgo.com/ac/?kl=wt-wt&q=*"
  ],
  "background": {
    "scripts": [
      "src/background/firefox/background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content.js"
      ]
    }
  ]
}