CSAF 2.0-2.1 converter

- addresses parts of oasis-tcs#673
- add new conformance target CSAF 2.0 CSAF 2.1 converter

csaf_2.1/prose/edit/src/conformance.md

@@ -50,6 +50,7 @@ The entities ("conformance targets") for which this document defines requirement
 * **CSAF full validator**: A CSAF extended validator that additionally performs informative tests.
 * **CSAF SBOM matching system**: A program that connects to or is an SBOM database and is able to manage CSAF documents as required
   by CSAF management system as well as matching them to SBOM components of the SBOM database.
+* **CSAF 2.0 to CSAF 2.1 converter**: A CSAF producer which takes a CSAF 2.0 document as input and converts it into a valid CSAF 2.1 document.
 
 ### Conformance Clause 1: CSAF document
 
@@ -489,4 +490,19 @@ A CSAF SBOM matching system satisfies the "CSAF SBOM matching system" conformanc
   * matching that CSAF document at all
   * marked with a given status
 
+### Conformance Clause 18: CSAF 2.0 to CSAF 2.1 converter
+
+A program satisfies the "CSAF 2.0 to CSAF 2.1 converter" conformance profile if the program fulfills the following two groups of requirements:
+
+Firstly, the program:
+
+* satisfies the "CSAF producer" conformance profile.
+* takes only CSAF 2.0 documents as input.
+* additionally satisfies the normative requirements given below.
+
+Secondly, the program fulfills the following for all items of:
+
+
+> A tool MAY implement options to convert other Markdown formats to GitHub-flavoured Markdown.
+
 -------

csaf_2.1/prose/edit/src/introduction-02-terminology-glossary.md

@@ -20,6 +20,9 @@ _Examples_: A physical file in a file system such as a source file, an object fi
 a specific version of a file in a version control system; a database table accessed via an HTTP request;
 an arbitrary stream of bytes returned from an HTTP request, a product URL, a common product enumeration value.
 
+CSAF 2.0 to CSAF 2.1 converter
+:    A CSAF producer which takes a CSAF 2.0 document as input and converts it into a valid CSAF 2.1 document.
+
 CSAF asset matching system
 :    program that connects to or is an asset database and is able to manage CSAF documents as
 required by CSAF management system