Examine source code of AoC Ranking

{
  "manifest_version": 2,
  "name": "Advent of Code Ranking",
  "version": "1.5.2",
  "description": "Visualize the ranking over time of a Advent of Code private leaderboard",
  "icons": {
    "48": "icons/aoc-ranking-48.png",
    "96": "icons/aoc-ranking-96.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://adventofcode.com/*/leaderboard/private/view/*"
      ],
      "js": [
        "ranking.js"
      ],
      "css": [
        "ranking.css"
      ]
    }
  ]
}