Improve Segment and Type property documentation to include a pointer the relevant Codes enum, where appropriate

[davebronson]

Property documentation in the Segment and Type classes should be updated to include a pointer to the relevant ClearHl7.Fhir.Codes enumeration, where appropriate. This would be a good opportunity to verify and update the existing hl7.org URL that's currently there. Example:

/// <summary>
/// ABS.2 - Transfer Medical Service Code.
/// </summary>
/// <remarks>
/// Suggested Value:
/// ClearHl7.Fhir.Codes.V282.CodeHospitalService enum
/// https://www.hl7.org/fhir/v2/0010
/// </remarks>
public CodedWithExceptions TransferMedicalServiceCode { get; set; }

[davebronson]

Property documentation has been improved, and released in V1.3.0. Implemented example:

/// <summary>
/// ABS.2 - Transfer Medical Service Code.
/// <para>Suggested: 0069 Hospital Service -> ClearHl7.Codes.V282.CodeHospitalService</para>
/// </summary>