Examine source code of mouselessV2

{
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/ext/content.js"
      ],
      "css": [
        "mouselessV2.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "src/ext/background.js"
    ]
  },
  "options_ui": {
    "page": "src/settings/options.html"
  },
  "icons": {
    "32": "icon-32.png",
    "48": "icon-48.png",
    "64": "icon-64.png",
    "128": "icon-128.png"
  },
  "browser_action": {
    "default_icon": {
      "32": "icon-32.png",
      "48": "icon-48.png",
      "64": "icon-64.png",
      "128": "icon-128.png"
    },
    "default_popup": "src/popup/index.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@mouselessV2"
    }
  },
  "permissions": [
    "<all_urls>",
    "clipboardRead",
    "clipboardWrite",
    "search",
    "storage",
    "tabs"
  ],
  "commands": {
    "changeTabLeft": {
      "description": "Change to tab left",
      "suggested_key": {
        "default": "Alt+N"
      }
    },
    "changeTabRight": {
      "description": "Change to tab right",
      "suggested_key": {
        "default": "Alt+P"
      }
    },
    "duplicateTab": {
      "description": "Duplicate current tab",
      "suggested_key": {
        "default": "Alt+U"
      }
    },
    "moveTabLeft": {
      "description": "Move tab left",
      "suggested_key": {
        "default": "Alt+Shift+N"
      }
    },
    "moveTabRight": {
      "description": "Move tab right",
      "suggested_key": {
        "default": "Alt+Shift+P"
      }
    },
    "tabAttach": {
      "description": "Attach current tab",
      "suggested_key": {
        "default": "Alt+Shift+A"
      }
    },
    "tabDetach": {
      "description": "Detach current tab",
      "suggested_key": {
        "default": "Alt+A"
      }
    }
  },
  "name": "mouselessV2",
  "description": "Browse the web, mouse not required.",
  "version": "3.3.0"
}