Examine source code of JiraStyle

{
  "manifest_version": 2,
  "name": "JiraStyle",
  "short_name": "JiraStyle",
  "author": "Aivar Loopalu",
  "homepage_url": "https://github.com/loopalu/JiraStyle",
  "description": "Changes the color of column in Jira board.",
  "version": "1.1.5",
  "icons": {
    "48": "icons/letter-j-48-blue.png",
    "96": "icons/letter-j-96-blue.png"
  },
  "background": {
    "scripts": [
      "extensionButtonFunctionality.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.jira.com/*"
      ],
      "js": [
        "pageFunctionality.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "aivar.loopalu@gmail.com"
    }
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/letter-j-48-blue.png",
      "96": "icons/letter-j-96-blue.png"
    },
    "default_title": "JiraStyle"
  }
}