manifest.json

{
    "version": "3.0.0",
    "manifest_version": 2,
    "name": "cat space",
    "description": "world of cats!",
    "icons": {
        "128": "./images/icon.png",
        "48": "./images/icon.png",
        "16": "./images/icon.png"
    },
    "browser_action": {
        "default_icon": {
            "128": "./images/icon.png",
            "48": "./images/icon.png",
            "16": "./images/icon.png"
        }
    },
    "chrome_url_overrides": {
        "newtab": "./new-tab.html"
    },
    "background": {
        "scripts": [
            "./background.js"
        ],
        "persistent": false
    },
    "permissions": []
}