docs: explains kubernetes deployment

README.rst

@@ -20,6 +20,19 @@ Some useful commands:
 Deploying on kubernetes
 =======================
 
+The file `deployment.yaml` contains several containers split in several
+deployments:
+
+- `nginx` to serve static files directly
+
+- `fresh` to run the application (and compile the latest translation)
+
+- an *initContainers* `upgrade` before `fresh` that upgrade the database schema
+  if there is a new `fresh` version.
+
+- `fresh-scheduler` to have the scheduler running.
+
+
 To create the initial database from an existing empty database::
 
    kubectl run -it fresh-dbcreate \