docs: arch diagram - use source of truth images (#1434)

docs/Architecture-Diagram.md

@@ -1,3 +1,7 @@
 # Swarm Architecture Diagram
 
-![Swarm Architecture Diagram](https://raw.githubusercontent.com/ethersphere/swarm/master/docs/img/Swarm-Architecture-Core.png "Swarm Architecture Diagram")
+![Swarm Architecture Diagram](https://raw.githubusercontent.com/ethersphere/swarm-guide/master/contents/img/high-level-components.svg?sanitize=true "Swarm Architecture Diagram")
+
+This diagram represents a high-level description of the most important components in Swarm.
+
+For more information refer to the [Swarm Documentation](https://swarm-guide.readthedocs.io) and to the [Architecture](https://swarm-guide.readthedocs.io/en/latest/architecture.html) chapter.