HTML Tag Error Checker

{
    "update_url": "https:\/\/clients2.google.com\/service\/update2\/crx",
    "version": "0.2.0",
    "background": {
        "service_worker": "js\/service-worker.js"
    },
    "action": {
        "default_icon": {
            "32": "img\/32.png",
            "48": "img\/48.png",
            "64": "img\/64.png",
            "200": "img\/200.png",
            "500": "img\/500.png"
        },
        "default_popup": "html\/popup.html"
    },
    "content_scripts": [
        {
            "js": [
                "js\/contents.js"
            ],
            "matches": [
                "<all_urls>"
            ]
        }
    ],
    "icons": {
        "32": "img\/32.png",
        "48": "img\/48.png",
        "64": "img\/64.png",
        "200": "img\/200.png",
        "500": "img\/500.png"
    },
    "options_page": "html\/setting.html",
    "permissions": [
        "activeTab",
        "storage",
        "tabs",
        "contextMenus"
    ],
    "web_accessible_resources": [
        {
            "resources": [
                "js\/*",
                "css\/*",
                "img\/*",
                "html\/*",
                "_locales\/*"
            ],
            "matches": [
                "http:\/\/*\/*",
                "https:\/\/*\/*"
            ]
        }
    ],
    "default_locale": "en",
    "name": "__MSG_extensionName__",
    "description": "__MSG_extensionDescription__",
    "manifest_version": 3
}