Examine source code of File Manager

{
    "manifest_version": 2,
    "name": "File Manager",
    "version": "0.2.2",
    "author": "Wang Wen Jie",
    "description": "File Manage Tool",
    "icons": {
        "96": "fm96.png"
    },

    // "browser_action":{
    //     "default_title":"Open File Manager"
    // },

    "browser_specific_settings": {
        "gecko": {
          "id": "{dd0dee29-5813-4dd9-8b3c-619d548b88bc}",
          "strict_min_version": "52.0"
        }
    },
    
    "default_locale":"en",
    
    "content_scripts":[
        {
            "matches":["file:///*"],
            "css":["a.css"],
            "js":["lib/jquery-3.4.1.min.js", "js/text_pane.js", "js/tree.js", "js/utils.js",  "js/android.js","js/m0.js", "js/main.js"]
        }
    ],

    "background":{
        "scripts":["js/utils.js", "js/background.js"]
    },


    "permissions":[
        // "activeTab",
        "bookmarks",
        "storage"
    ]
}