Examine source code of Fantasy Sync Assistant

{
  "manifest_version": 2,
  "name": "Fantasy Sync Assistant",
  "version": "1.1.2",
  "description": "Syncs ESPN fantasy baseball transactions to a Fantrax mirrored league by replaying each move on the Fantrax Commissioner pages, keeping rosters current for accurate free agent scouting.",
  "author": "James Wazam",
  "icons": {
    "16": "assets/icon-16.png",
    "32": "assets/icon-32.png",
    "48": "assets/icon-48.png",
    "96": "assets/icon-96.png",
    "128": "assets/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "fantasy-sync-assistant@fantasy-sync",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "*://fantasy.espn.com/*",
    "*://www.fantrax.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icon-16.png",
      "32": "assets/icon-32.png",
      "48": "assets/icon-48.png",
      "96": "assets/icon-96.png"
    },
    "default_title": "Fantasy Sync Assistant"
  },
  "content_scripts": [
    {
      "matches": [
        "*://fantasy.espn.com/*recentactivity*",
        "*://fantasy.espn.com/*draftrecap*"
      ],
      "js": [
        "espn.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "*://www.fantrax.com/*claimDrop*",
        "*://www.fantrax.com/*trade.go*",
        "*://www.fantrax.com/*playerImport.go*"
      ],
      "js": [
        "fantrax.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "commands": {
    "step-transaction": {
      "suggested_key": {
        "default": "F7"
      },
      "description": "Next: process one transaction. or Stop: pause auto-run if active"
    },
    "next-transaction": {
      "suggested_key": {
        "default": "F8"
      },
      "description": "Auto: process all transactions automatically"
    }
  }
}