feat: OpenXML.Excel.File.get_Cell ( Fixes #6 )

Adding docs

Author: StartAutomating

Types/OpenXML.Excel.Worksheet/get_Cell.ps1

@@ -1,16 +1,32 @@
-$excelCells = [Ordered]@{
-
-}
-$sharedStrings = $this.OpenXML.Parts['/xl/sharedStrings.xml'].Content
+<#
+.SYNOPSIS
+    Gets cells from Excel
+.DESCRIPTION
+    Gets individual cells in an Excel worksheet.
+.EXAMPLE
+    Get-OpenXML ./Examples/Sum.xlsx |
+        Select-Object -ExpandProperty Worksheets |
+        Select-Object -ExpandProperty Cell
+#>
+param()
+$excelCells = [Ordered]@{}
+# Get each row from our sheet data
 foreach ($worksheetRow in $this.content.worksheet.sheetdata.row) {
+    # and get each column from each row
     foreach ($worksheetColumn in $worksheetRow.c) {
-        
-        $excelCells[$worksheetColumn.r] = 
+        # The `r` attribute contains the cell coordinate
+        $excelCells[$worksheetColumn.r] =
+            # Excel cells are always numbers.
+            # If the cell contains a string, it is actually stored as an index in "sharedStrings"
             if ($worksheetColumn.t -eq 's') {
-                $this.OpenXML.SharedStrings[$worksheetColumn.v -as [int]]
+                # which makes indexing awfully easy (and has the side-effect of reducing the total file size for worksheets with similar text)
+                $this.OpenXML.SharedStrings[$worksheetColumn.v]
             } else {
+                # Otherwise, the value should be `v`.
                 $worksheetColumn.v   
             }
     }
 }
-$excelCells
+
+# Return our cells as dictionary
+return $excelCells