docs update

I have added some information to the TOPFARM main page as well as the user guide. Also, I edited the notebooks to make them clearer and added an example for optimizations with hub height, turbine type and yaw angle (unconstrained) as design variables.

One suggestion is to merge the examples on bathymetry and exclusion zone, as they seem to be the same optimization problem.

topfarm/cost_models/cost_model_wrappers.py

@@ -203,7 +203,6 @@ class AEPCostModelComponent(CostModelComponent):
                  output_unit="", additional_input=[], additional_output=[], max_eval=None,
                  output_key="AEP", **kwargs):
         """Initialize Sub class of the CostModelComponent for AEP maximization
-        
         Parameters
         ----------
         input_keys : list of str
@@ -233,20 +232,16 @@ class AEPCostModelComponent(CostModelComponent):
         CostModelComponent.__init__(self, input_keys, n_wt, cost_function,
                                     cost_gradient_function=cost_gradient_function,
                                     output_key=output_key, output_unit=output_unit,
-                                    additional_input=additional_input,              
+                                    additional_input=additional_input,      
                                     additional_output=additional_output,
                                     max_eval=max_eval, maximize=True, **kwargs)
         
-
-
 class AEPMaxLoadCostModelComponent(CostModelComponent, PostConstraint):
     """Wrapper for pure-Python cost functions"""
-    
     def __init__(self, input_keys, n_wt, aep_load_function, max_loads,
                  aep_load_gradient=None, output_keys=["AEP", 'loads'], step={},
                  maximize=True, **kwargs):
         """Initialize Sub class of the CostModelComponent for AEP maximization and load constraints
-        
         Parameters
         ----------
         input_keys : list of str