feat: add stops-import.txt

src/stops-import/stops-import.txt

@@ -0,0 +1,33 @@
+@startuml
+start
+:check user authorization;
+if (Authorized?) then (yes)
+  :check number of imports;
+  if (number?) equals (2) then
+    :check stops in storage;
+    if (Stop storage available?) then (yes)
+      :check stops from import;
+        if (Is stop import empty?) then (yes)
+	  end
+	else
+	  :check zones from import;
+        if (Is zone import empty?) then (yes)
+	  end
+	else
+	  :process zones from import;
+	  :process stops from import;
+	  :delete obsolete records in storage;
+	  :return all records from storage;
+	endif
+	endif
+    else
+      end
+    endif
+  else
+    end
+  endif
+else (no)
+  end
+endif
+end
+@enduml