added Revit 2020 SDK files

SDK/Samples/ProjectInfo/CS/Converters/TimeZoneConverter.cs

@@ -0,0 +1,42 @@
+using System.ComponentModel;
+
+namespace Revit.SDK.Samples.ProjectInfo.CS
+{
+    /// <summary>
+    /// Converter used to convert TimeZone
+    /// </summary>
+    public class TimeZoneConverter : TypeConverter
+    {
+        #region Methods
+        /// <summary>
+        /// Returns whether this object supports a standard set of values that can be
+        /// picked from a list, using the specified context.
+        /// </summary>
+        /// <returns>true</returns>
+        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
+        {
+            return true;
+        }
+
+        /// <summary>
+        /// Returns whether the collection of standard values returned from System.ComponentModel.TypeConverter.GetStandardValues()
+        /// is an exclusive list.
+        /// </summary>
+        /// <returns>true</returns>
+        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
+        {
+            return true;
+        }
+
+        /// <summary>
+        /// Returns a collection of standard values from the default context for the
+        /// data type this type converter is designed for.
+        /// </summary>
+        /// <returns>Element collection retrieved through filtering current Revit document elements</returns>
+        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
+        {
+            return new StandardValuesCollection(RevitStartInfo.TimeZones);
+        }
+        #endregion
+    };
+}