Examine source code of BiliBili Player Tool

{
  "manifest_version": 3,
  "name": "BiliBili Player Tool",
  "version": "1.2",
  "description": "apply youtube shortcuts (j, k, l, t, <, >) for BiliBili Player",
  "browser_specific_settings": {
    "gecko": {
      "id": "bilibili-player-tool@leatherpants",
      "strict_min_version": "58.0"
    }
  },
  "icons": {
    "48": "icons/bilibili-48.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.bilibili.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}