Parent issue: #401
Relates to: #401 (comment)

@da2ce7 proposed adding a version field to the configuration and also a namespace.

[torrust_tracker]
version = "1.0.0"

[torrust_tracker.logging]
log_level = "info"

{
  "torrust_tracker": {
    "version": "1.0.0",
    "logging": {
      "log_level": "info"
    }
  }
}

@da2ce7, is this the way you thought about including the namespace? I think it's a good idea because it allows merging different app configurations into a single TOML file (for example, a single Tracker and Index). However, it adds one level of indentation to the whole field.