How to document a method within your C# library's public API

YourClass.cs

namespace YourNamespace {
  /// <summary>
  /// Put a description of the class here.
  /// </summary>
  public class YourClass {
  
    /// <summary>
    /// Put a description of the method here.
    /// </summary>
    /// <param name="key">Put a description of the parameter here.</param>
    /// <param name="defaultValue">Put a description of the other parameter here.</param>
    /// <returns>Put a description of the returned value here.</returns>
    public bool Get(string key, bool defaultValue = default(bool)) {
        return data.Get(key, defaultValue);
    }
  }
}