Examine source code of Case Changer

{
  "manifest_version": 2,
  "name": "Case Changer",
  "version": "1.0",
  "description": "Change text case.",
  "author": "Web Guy",
  "homepage_url": "https://github.com/webguyio/support",
  "icons": {
    "256": "icon.png"
  },
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "transform-titlecase": {
      "description": "Title Case"
    },
    "transform-lowercase": {
      "description": "lower case"
    },
    "transform-uppercase": {
      "description": "UPPER CASE"
    },
    "transform-sentencecase": {
      "description": "Sentence case"
    },
    "transform-capitalcase": {
      "description": "Capital Case"
    },
    "transform-pascalcase": {
      "description": "PascalCase"
    },
    "transform-camelcase": {
      "description": "camelCase"
    },
    "transform-kebabcase": {
      "description": "kebab-case"
    },
    "transform-traincase": {
      "description": "Train-Case"
    },
    "transform-snakecase": {
      "description": "snake_case"
    },
    "transform-screamingsnakecase": {
      "description": "SCREAMING_SNAKE_CASE"
    },
    "transform-flatcase": {
      "description": "flatcase"
    },
    "transform-upperflatcase": {
      "description": "UPPERFLATCASE"
    },
    "transform-alternatingcase": {
      "description": "aLtErNaTiNg CaSe"
    },
    "transform-randomcase": {
      "description": "RaNdOm CaSe"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "case-changer@webguyio",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}