Added Example for using PivotFilter

Examples/PivotTableFilters/testPivotFilter.ps1

@@ -0,0 +1,23 @@
+Import-Module ..\..\ImportExcel.psd1 -Force
+
+$xlFile=".\testPivot.xlsx"
+Remove-Item $xlFile -ErrorAction Ignore
+
+
+$data =@"
+Region,Area,Product,Units,Cost
+North,A1,Apple,100,.5
+South,A2,Pear,120,1.5
+East,A3,Grape,140,2.5
+West,A4,Banana,160,3.5
+North,A1,Pear,120,1.5
+North,A1,Grape,140,2.5
+"@ | ConvertFrom-Csv
+
+$data |
+    Export-Excel $xlFile -Show `
+        -AutoSize -AutoFilter `
+        -IncludePivotTable `
+        -PivotRows Product `
+        -PivotData @{"Units"="sum"} `
+        -PivotFilter Region, Area `