Add missing page in documentation

Signed-off-by: Denislav Prinov <denislav.prinov@bosch.com>

docs/README.md

@@ -3,7 +3,7 @@
 Eclipse hawkBit™ is a domain independent back-end framework for rolling out software updates to constrained edge devices as well as more powerful controllers and gateways connected to IP based networking infrastructure.
 
 <p align="center">
-  <img src="images/hawkBit_overview.jpeg" alt="eclipse foundation logo" width="1200">
+  <img src="images/hawkBit_overview.png" alt="eclipse foundation logo" width="1200">
 </p>
 
 ---

docs/_sidebar.md

@@ -3,6 +3,7 @@
   - [What is hawkBit](what-is-hawkbit.md)
   - [Quick Start](quick-start.md)
   - [Features](features.md)
+  - [Architecture](architecture.md)
 
 - Guides
   - [Run hawkBit](run-hawkbit.md)

docs/architecture.md

@@ -0,0 +1,5 @@
+### Overview of hawkBit modules and used 3rd party technology:
+<p align="center">
+  <img src="images/architecture.png" alt="Clustering Diagram" width="1100"/>
+</p>
+