Right-to-left enforcer for Contentful editor

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Right-to-left enforcer for Contentful editor",
  "description": "Forces editors to use a right-to-left direction when editing Arabic text on Contentful",
  "version": "1.0",
  "icons": {
    "16": "images/icon_16.png",
    "48": "images/icon_48.png",
    "128": "images/icon_128.png"
  },
  "content_scripts": [
    {
      "js": [
        "content_script.js"
      ],
      "matches": [
        "*://app.contentful.com/*"
      ],
      "run_at": "document_idle"
    }
  ]
}