update arch

Readme.md

@@ -9,3 +9,23 @@ you can rebuild a standalone vault srver with a consul database snaphot with
 make vault-dev FILE=./yourconsulsnaphot.snap
 ```
 
+
+
+## Architecture
+
+```mermaid
+flowchart LR
+    subgraph Home
+    oscar[oscar]
+    gerard[gerard]
+    local[lan]
+    end
+    subgraph Cloud
+    merlin[merlin]
+    end
+  local[lan] <--> oscar
+  oscar <--> merlin
+  gerard <--> merlin
+  merlin <--> internet 
+  
+```