MultiColumn: added missing documentation

Source/QuestPDF/Fluent/MultiColumnExtensions.cs

@@ -9,21 +9,52 @@ public class MultiColumnDescriptor
 {
     internal MultiColumn MultiColumn { get; } = new MultiColumn();
         
+    /// <summary>
+    /// Configures the horizontal spacing between adjacent columns in the layout.
+    /// </summary>
+    /// <remarks>
+    /// This method affects the visual presentation of the column arrangement.
+    /// Positive values increase separation, while negative values may cause overlap.
+    /// </remarks>
     public void Spacing(float value, Unit unit = Unit.Point)
     {
         MultiColumn.Spacing = value.ToPoints(unit);
     }
     
+    /// <summary>
+    /// Defines the number of vertical columns in the layout.
+    /// </summary>
+    /// <remarks>
+    /// This method determines the basic structure of the grid layout.
+    /// Setting this value will redistribute the existing elements across the new column count.
+    /// </remarks>
     public void Columns(int value = 2)
     {
+        if (value <= 1)
+            throw new DocumentComposeException("The 'MultiColumn.Columns' value should be higher than 1.");
+        
         MultiColumn.ColumnCount = value;
     }
-        
+
+    /// <summary>
+    /// Controls the content distribution across columns to achieve balanced heights.
+    /// </summary>
+    /// <remarks>
+    /// <para>When enabled: content flow is adjusted to equalize column heights; each column will have approximately the same height.</para>
+    /// <para>When disabled: layout occupies the full vertical space, the last column may be shorter or empty, depending on content quantity.</para>
+    /// </remarks>
     public void BalanceHeight(bool enable = true)
     {
         MultiColumn.BalanceHeight = enable;
     }
 
+    /// <summary>
+    /// Retrieves a container for the primary content to be distributed across multiple columns.
+    /// </summary>
+    /// <remarks>
+    /// The returned container serves as the main content area for the multi-column layout.
+    /// It supports all available layout elements and automatically divides its content among the defined columns.
+    /// </remarks>
     public IContainer Content()
     {
         if (MultiColumn.Content is not Empty)
@@ -34,6 +65,13 @@ public class MultiColumnDescriptor
         return container;
     }
     
+    /// <summary>
+    /// Retrieves a container for content positioned between columns in the layout.
+    /// </summary>
+    /// <remarks>
+    /// The container's dimensions are determined by the height of the columns and the configured spacing.
+    /// This container supports all available layout elements, allowing for flexible design of inter-column content.
+    /// </remarks>
     public IContainer Spacer()
     {
         if (MultiColumn.Spacer is not Empty)
@@ -50,6 +88,13 @@ public static class MultiColumnExtensions
     /// <summary>
     /// Creates a multi-column layout within the current container element.
     /// </summary>
+    /// <remarks>
+    /// A multi-column layout organizes content into vertical columns, similar to a newspaper or magazine layout.
+    /// This approach allows for efficient use of horizontal space and can improve readability, especially
+    /// for wide containers or screens. The content flows from one column to the next, and the number of
+    /// columns can be adjusted based on the container's width or specific design requirements.
+    /// </remarks>
+    /// <param name="handler">The action to configure the column's content and behavior.</param>
     public static void MultiColumn(this IContainer element, Action<MultiColumnDescriptor> handler)
     {
         var descriptor = new MultiColumnDescriptor();