Added some standard indicators

Src/Myc.Trade.DataArray.pas

@@ -2,10 +2,10 @@ unit Myc.Trade.DataArray;
 
 interface
 
-uses
-    Myc.Trade.DataPoint;
-
 type
+    // A series is an array of values with the newest ite at index=0. Each series counts the total of added items since creation, but
+    // it actually may contain less items, because the array size is limited by the lookback parameter, when adding items.
+    // Series are immutable.
     TMycDataArray<T> = record
     private
         const
@@ -21,7 +21,9 @@ type
         function GetItems(Idx: Int64): T; inline;
     public
         constructor Create(const AChunks: TArray<TChunk>; ACount, ATotalCount: Int64);
+        // Add a singe item
         function Add(const Data: T; Lookback: Int64): TMycDataArray<T>; overload;
+        // Add a ranmge of items
         function Add(const Data: array of T; First, Count, Lookback: Int64): TMycDataArray<T>; overload;
         class function CreateEmpty: TMycDataArray<T>; static;
         // Helper to create a data array from a raw TArray.