Add XML doc for public types and methods

SpreadCheetah/SourceGeneration/EmptyWorksheetRowContext.cs

@@ -6,8 +6,16 @@
 
 namespace SpreadCheetah.SourceGeneration;
 
+/// <summary>
+/// Used by the SpreadCheetah source generator for types without valid publicly visible getters.
+/// Should not be used directly.
+/// </summary>
 public static class EmptyWorksheetRowContext
 {
+    /// <summary>
+    /// Creates metadata for a type without valid publicly visible getters.
+    /// Should not be used directly.
+    /// </summary>
     public static WorksheetRowTypeInfo<T> CreateTypeInfo<T>() => WorksheetRowMetadataServices.CreateObjectInfo<T>(AddHeaderRowAsync, AddAsRowAsync, AddRangeAsRowsAsync);
 
     private static ValueTask AddHeaderRowAsync(Spreadsheet spreadsheet, StyleId? _, CancellationToken token)

SpreadCheetah/Spreadsheet.cs

@@ -320,6 +320,12 @@ public ValueTask AddRowAsync(IList<StyledCell> cells, RowOptions? options, Cance
             : Worksheet.AddRowAsync(cells, options, token);
     }
 
+    /// <summary>
+    /// Add a row of header names in the active worksheet.
+    /// The header name in each cell will match the property name from the given type.
+    /// A style can optionally be applied to all the cells in the row.
+    /// The <see cref="WorksheetRowTypeInfo{T}"/> type must be generated by a source generator.
+    /// </summary>
     public ValueTask AddHeaderRowAsync<T>(WorksheetRowTypeInfo<T> typeInfo, StyleId? styleId = null, CancellationToken token = default)
     {
         ArgumentNullException.ThrowIfNull(typeInfo);