Examine source code of EventMaker

{
  "name": "EventMaker",
  "version": "1.0.0",
  "manifest_version": 2,
  "description": "Highlight a date to automatically create a Google Calendar event.",
  "homepage_url": "https://www.regexr.tech",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "regexr@regexrtech.com"
    }
  },
  "browser_action": {
    "default_title": "EventMaker"
  },
  "permissions": [
    "https://*/*",
    "http://*/*",
    "tabs"
  ]
}