Examine source code of Markdown Fastmail Notes

{
  "manifest_version": 2,
  "name": "Markdown Fastmail Notes",
  "version": "1.0.5resigned1",
  "description": "Render plain text Markdown formatted Fastmail Notes in HTML",
  "homepage_url": "https://github.com/kanru/markdown-fastmail-notes",
  "applications": {
    "gecko": {
      "id": "{ac27335e-ace4-4ca0-8b11-fd0e10d00be7}",
      "strict_min_version": "42.0",
      "strict_max_version": "*"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.fastmail.com/*"
      ],
      "js": [
        "commonmark.js",
        "mmdwn.js"
      ],
      "run_at": "document_idle"
    }
  ]
}