Examine source code of Word Replacer Max

{
  "commands": {
    "input-replacement": {
      "description": "Execute replacements on all input elements",
      "suggested_key": {
        "default": "Ctrl+Shift+E",
        "mac": "Command+Shift+E"
      }
    }
  },
  "description": "Seamlessly replace text on any web page.",
  "homepage_url": "https://github.com/dan-lovelace/word-replacer-max",
  "icons": {
    "64": "assets/img/word-replacer-max-logo_64.png",
    "128": "assets/img/word-replacer-max-logo_128.png",
    "256": "assets/img/word-replacer-max-logo_256.png"
  },
  "manifest_version": 2,
  "name": "Word Replacer Max",
  "permissions": [
    "contextMenus",
    "storage",
    "https://api.wordreplacermax.com/*"
  ],
  "version": "0.21.0",
  "author": "dan@wordreplacermax.com",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "web_accessible_resources": [
    "assets/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://wordreplacermax.com/*"
      ],
      "js": [
        "auth.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "exclude_matches": [
        "https://wordreplacermax.com/*"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{702752b1-b39f-4a63-ba36-58a8303243d5}"
    }
  }
}