Examine source code of COVID-19 Blocker

{
  "name": "COVID-19 Blocker",
  "version": "1.3",
  "description": "Blocking excessive COVID-19 articles.",
  "author": "Gvozden Despotovski",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "badge.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.facebook.com/*",
        "https://*.reddit.com/*",
        "https://*.twitter.com/*"
      ],
      "js": [
        "filter.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "images/icon16.png",
      "28": "images/icon28.png",
      "32": "images/icon32.png",
      "48": "images/icon48.png",
      "64": "images/icon64.png",
      "128": "images/icon128.png",
      "256": "images/icon256.png",
      "512": "images/icon512.png"
    },
    "default_title": "COVID-19 Blocker",
    "default_popup": "popup.html"
  },
  "permissions": [
    "https://*.facebook.com/*",
    "https://*.reddit.com/*",
    "https://*.twitter.com/*",
    "storage",
    "background"
  ]
}