Add data flow diagram

doc/data-flow.md

@@ -0,0 +1,39 @@
+# Data Flow from confif & auth to final website
+
+```mermaid
+flowchart TB
+    a0(config)
+    a1(auth)
+    c4k(c4k-website)
+    sec(website-build-secret)
+    b(nginx-deployment\ninitContainer)
+    c(website-build-cron)
+    d(repo.prod.meissa.de)
+    e[(content-volume)]
+    f(nginx)
+    g((serve website))
+    h(website-user)
+    subgraph dockerImage
+        j((build website))
+        i((pull website repo))
+        unpack((unpack website data))
+        exec((execute scripts))
+        if0{scripts exist}
+        i -- zip file --> unpack
+        unpack -- website data --> if0        
+        if0 -- yes --> exec
+        exec -- modified\n website data--> j
+        if0 -- no\n unmodified website data --> j
+    end
+    a0 -- configuration data --> c4k
+    a1 -- authorization data --> c4k
+    c4k -- container specific config &\n build specific env vars--> b & c
+    c4k -- build specific secret env vars --> sec
+    sec -- secret env vars --> b & c
+    b & c -- environment vars\n from secret and c4k-website --> dockerImage
+    d -- build repo --> dockerImage
+    dockerImage -- website files --> e
+    e -- website files --> f
+    f -- website files --> g
+    g -- rendered page --> h
+```