1. Logging
    1. Getting started with logging in Rust
    2. Simple Logger new
    3. Simple Logger init
    4. Simple Logger level
    5. Logging with log4rs
    6. Simple use of env_logger
    7. env_logger with Builder
  2. Tracing
    1. Tracing demo
    2. Tracing in a library
    3. Tracing in an application
    4. Simple tracing configuration with RUST_LOG environment variable