Examine source code of heiseForumExpander

{
  "description": "Load all posts from the heise.de web page. When opening the comments section from an article, the topics and their posts will be loaded and displayed on the same page. So you don't have to open and load each page separately",
  "author": "Hearted Mother",
  "manifest_version": 2,
  "name": "heiseForumExpander",
  "version": "1.1",
  "homepage_url": "http://heartedmother.bplaced.net",
  "icons": {
    "48": "icons/48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.heise.de/forum/*"
      ],
      "js": [
        "heiseForumExpander.js"
      ]
    }
  ]
}