Update model struct in docs

docs/developments/julia_structs.qmd

@@ -8,15 +8,20 @@ Below the composite type that represents all different aspects of a `Wflow.Model
 network, parameters, clock, model type, configuration and input and output.
 
 ```julia
-struct Model{L,V,R,W,T}
-    config::Config   # all configuration options
-    network::Network # connectivity information, directed graph
-    lateral::L       # lateral model that holds lateral state, moves along network
-    vertical::V      # vertical model that holds vertical state, independent of each other
-    clock::Clock     # to keep track of simulation time
-    reader::R        # provides the model with dynamic input
-    writer::W        # writes model output
-    type::T          # model type
+struct Model{
+    L <: Lateral,
+    V <: AbstractLandSurface,
+    R <: NCReader,
+    T <: AbstractModelType,
+} <: AbstractModel{T}
+    config::Config    # all configuration options
+    network::Network  # connectivity information, directed graph
+    lateral::L        # lateral model that holds lateral state, moves along network
+    vertical::V       # vertical model that holds vertical state, independent of each other
+    clock::Clock      # to keep track of simulation time
+    reader::R         # provides the model with dynamic input
+    writer::Writer    # writes model output
+    type::T           # model type
 end
 ```