Add proxy specs template

Author: clauspruefer

specs/xml/NLAPP-XML-SPECS.md

@@ -0,0 +1,7 @@
+# 4. Next Level Application Proxy Protocol (NLAPP)
+
+## 4.1. Overview
+
+This specification is currently under development.
+
+Please refer to the [development status page](https://www.der-it-pruefer.de/network/Exemplary-HTTP-Processing-Protocol-Design) for the latest updates.

specs/xml/README.md

@@ -7,6 +7,7 @@ This directory contains XML service metadata specifications for the Next Level A
 1. [Next Level Application Metadata Protocol (NLAMP)](./NLAMP-XML-SPECS.md)
 2. [Next Level Application File Protocol (NLAFP)](./NLAFP-XML-SPECS.md)
 3. [Next Level Application Session Protocol (NLASP)](./NLASP-XML-SPECS.md)
+4. [Next Level Application Proxy Protocol (NLAPP)](./NLAPP-XML-SPECS.md)
 
 ## 1.2. Development Status