This package provides a utility to load configuration using Viper. It reads two configuration files:

1. global.json: A global configuration file whose path is specified by the GLOBAL_CONFIG environment variable.
2. Environment-specific configuration files (development.json, production.json, staging.json): These files are located in the config directory of the project and are selected based on the ENV environment variable.

1. Set the GLOBAL_CONFIG environment variable to the path of the global.json file.
2. Set the ENV environment variable to one of development, production, or staging. If not set, it defaults to development.
3. Call config.InitConfig() to initialize the configuration.