Initial commit of the ClosedXML library

Establishes the foundational structure, core Excel functionality, and tooling.

- Implements base components for cells, ranges, columns, and rows.
- Integrates a custom calculation engine with a wide range of Excel functions.
- Adds comprehensive support for styling, conditional formatting, data validation, comments, pictures, and charts.
- Configures build setup, project metadata (NuGet), and developer guidelines.
- Includes editor and Git attributes for consistent code style and line endings.

ClosedXML_Examples/Ranges/ClearingRanges.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Linq;
+using ClosedXML.Excel;
+
+
+namespace ClosedXML_Examples.Ranges
+{
+    public class ClearingRanges : IXLExample
+    {
+        #region Methods
+
+        // Public
+        public void Create(String filePath)
+        {
+            var workbook = new XLWorkbook();
+            var ws = workbook.Worksheets.Add("Clearing Ranges");
+            foreach (var ro in Enumerable.Range(1, 10))
+            {
+                foreach (var co in Enumerable.Range(1, 10))
+                {
+                    var cell = ws.Cell(ro, co);
+                    cell.Value = cell.Address.ToString();
+                    cell.Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
+                    cell.Style.Fill.BackgroundColor = XLColor.Turquoise;
+                    cell.Style.Font.Bold = true;
+                }
+            }
+
+            // Clearing a range
+            ws.Range("B1:C2").Clear();
+
+            // Clearing a row in a range
+            ws.Range("B4:C5").Row(1).Clear();
+
+            // Clearing a column in a range
+            ws.Range("E1:F4").Column(2).Clear();
+
+            // Clear an entire row
+            ws.Row(7).Clear();
+
+            // Clear an entire column
+            ws.Column("H").Clear();
+
+            workbook.SaveAs(filePath);
+        }
+
+        // Private
+
+        // Override
+
+
+        #endregion
+    }
+}