Examine source code of single-spa Inspector

{
  "manifest_version": 2,
  "name": "single-spa Inspector",
  "short_name": "sspa Inspect",
  "version": "0.6.0",
  "author": "Anthony Frehner",
  "homepage_url": "https://github.com/single-spa/single-spa-inspector",
  "description": "A devtools panel for single-spa applications",
  "browser_action": {
    "default_icon": "./logo-white-bgblue.png",
    "default_title": "single-spa Inspector"
  },
  "icons": {
    "48": "./logo-white-bgblue.png",
    "96": "./logo-white-bgblue.png"
  },
  "devtools_page": "./build/main.html",
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "js": [
        "./build/contentScript.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "./build/backgroundScript.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ce63669e-1a4c-4c41-b95b-d71bd7ce0c26}"
    }
  }
}