Improve diagram in the RAG DA

[vburckhardt]

Description

https://github.com/terraform-ibm-modules/terraform-ibm-rag-sample-da/blob/main/reference-architecture/ce_da_architecture_diagram.drawio.svg

The diagram should show:

• The uploaded pdf to watson project
• Location of watson project
• Configuration made to existing pipeline (current diagram mentions DA rather that infrastructure)
• ....