added xttsv4 guide

Author: macsdata

data-platform/modernise/transportable-tablespace/README.MD

@@ -15,6 +15,8 @@ Reviewed: 04.01.2024
 
 - [Seamless Cross-Platform/Endian Database Migration with Minimal Downtime](https://www.youtube.com/watch?v=OUsaZoBUHBY)
   - Cload Coaching Webinar delivered by Marcus Doeringer and the EMEA Lift team (Poornima Veeraiah, Suresh Baral) explaining XTTSv4 and Full Transportable Export/Import FTEX migration method including a technical demo and best practices 
+- [Migration Guide: XTTSv4 / Full Transportable Export/Import](https://macsdata.netlify.app/oradb/migration/guides/xttsv4-ftex)
+  - Detailed, step-by-step guide showing how to perform a cross platform/endian database migration using XTTSv4 and Full Transportable Export/Import on Marcus Doeringer's public platform
 
 # Useful Links