docs: readme files

Signed-off-by: Manuel Morejon <manuel@mmorejon.io>

Author: mmorejon

README.en.md

@@ -4,7 +4,7 @@
 
 <div align="center">
 
-<img src="./assets/book-cover.jpg" alt="Once Upon a Time Kubernetes Book Cover" width="300"/>
+<img src="https://github.com/mmorejon/once-upon-a-time-k8s/blob/main/assets/book-cover.jpg" alt="Once Upon a Time Kubernetes Book Cover" width="300"/>
 
 ### 📚 OCI Data Volumes
 

README.md

@@ -4,7 +4,7 @@
 
 <div align="center">
 
-<img src="./assets/book-cover.jpg" alt="Portada Libro Érase una vez Kubernetes" width="300"/>
+<img src="https://github.com/mmorejon/erase-una-vez-k8s/blob/main/assets/book-cover.jpg" alt="Portada Libro Érase una vez Kubernetes" width="300"/>
 
 ### 📚 Volúmenes OCI de Datos