Added documentation of barcode file name

src/site/markdown/configuration.md.vm

@@ -85,6 +85,12 @@ The folder is relative to the current working directory.
 The output file is a csv file with the first column containing the identifiers from the input file and then the random
 numbers encoded in the different encodings defined in the [Random](#Random) section.
 
+The generated barcodes will be placed also in the output folder and have the following filename:
+`<barcode type>-<encoding>-<identifier>.<filetype>`.
+
+A barcode for an identifier `0001` for a `qrcode` with random number encoding `hex` as `png`-file is named
+`qrcode-hex-0001.png`.
+
 $h3 Random
 
 $h4 Overview