feat: OpenXML.Excel.File.get_Formula ( Fixes #26 )

Author: StartAutomating

Types/OpenXML.Excel.Worksheet/get_Formula.ps1

@@ -0,0 +1,9 @@
+$formulaCells = [Ordered]@{}
+foreach ($worksheetRow in $this.content.worksheet.sheetdata.row) {
+    foreach ($worksheetColumn in $worksheetRow.c) {
+        if ($worksheetColumn.f) {
+            $formulaCells[$worksheetColumn.r] = $worksheetColumn.f
+        }        
+    }
+}
+$formulaCells