Update image in readme and fix typo.

README.md

@@ -116,7 +116,7 @@ func main() {
 	for k, v := range values {
 		xlsx.SetCellValue("Sheet1", k, v)
 	}
-	xlsx.AddChart("Sheet1", "E1", `{"type":"bar3D","series":[{"name":"=Sheet1!$A$2","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$2:$D$2"},{"name":"=Sheet1!$A$2","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$3:$D$3"},{"name":"=Sheet1!$A$3","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$4:$D$4"}],"title":{"name":"Fruit 3D Line Chart"}}`)
+	xlsx.AddChart("Sheet1", "E1", `{"type":"bar3D","series":[{"name":"=Sheet1!$A$2","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$2:$D$2"},{"name":"=Sheet1!$A$3","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$3:$D$3"},{"name":"=Sheet1!$A$4","categories":"=Sheet1!$B$1:$D$1","values":"=Sheet1!$B$4:$D$4"}],"title":{"name":"Fruit 3D Line Chart"}}`)
 	// Save xlsx file by the given path.
 	err := xlsx.SaveAs("./Workbook.xlsx")
 	if err != nil {