Update index.en.adoc

modules/ROOT/pages/index.en.adoc

@@ -70,6 +70,7 @@ link:https://www.ferd-net.de/standards/zugferd/index.html[ZUGFeRD]/Factur-X is a
 * Swiss army knife link:https://github.com/AgID/EeISI-mapper/[conversion tool], use e.g. it's commandline tool EIGOR to convert interchangably between CII, UBL and FatturaPA
 * A little python script to link:https://github.com/ZUGFeRD/einvoice-anonymizer[remove personal data from CII] invoices 
 * Philip Helger published a link:https://github.com/phax/en16931-cii2ubl[java library to convert UN/CEFACT CII to UBL]
+* Auratech published a tool cii to ubl and vice versa https://github.com/Auratechcom/converter_ubl_cii_invoice_xml
 * There is a link:https://github.com/jcthiele/OpenXRechnungToolbox[OpenXRechnungToolbox] to visualize and validate XRechnung and Leitweg-IDs
 * There is an interesting link:https://github.com/svanteschubert/en16931-data-extractor[parser] for the EN16931 specification documents
 * xpdf has a interesting link:https://www.xpdfreader.com/pdfdetach-man.html[pdfdetach] command line tool to extract the XML from the PDF