maintain snake in api calls

there were only two methods using camel case for arguments

src/ifcopenshell-python/ifcopenshell/api/layer/add_layer.py

@@ -19,7 +19,7 @@ import ifcopenshell
 from typing import Optional
 
 
-def add_layer(file: ifcopenshell.file, Name: Optional[str] = None) -> ifcopenshell.entity_instance:
+def add_layer(file: ifcopenshell.file, name: str = "Unnamed") -> ifcopenshell.entity_instance:
     """Adds a new layer
 
     An IFC layer is like a CAD layer. Portions of an object's geometry
@@ -34,13 +34,13 @@ def add_layer(file: ifcopenshell.file, Name: Optional[str] = None) -> ifcopenshe
     Some software that are still based on layers, such as Tekla or ArchiCAD
     may also use this layer information for filtering.
 
-    :param Name: The name of the layer. Defaults to "Unnamed".
-    :type Name: str, optional
+    :param name: The name of the layer. Defaults to "Unnamed".
+    :type name: str, optional
     :return: The newly created IfcPresentationLayerAssignment element
     :rtype: ifcopenshell.entity_instance
 
     Example:
 
-        ifcopenshell.api.run("layer.add_layer", model, Name="AI-WALL-FULL-DIMS-N")
+        ifcopenshell.api.run("layer.add_layer", model, name="AI-WALL-FULL-DIMS-N")
     """
-    return file.create_entity("IfcPresentationLayerAssignment", Name=Name or "Unnamed")
+    return file.create_entity("IfcPresentationLayerAssignment", Name=name)

src/ifcopenshell-python/ifcopenshell/api/layer/assign_layer.py

@@ -59,7 +59,7 @@ def assign_layer(
         ifcopenshell.api.run("geometry.edit_object_placement", model, product=wall)
 
         # Now let's create a layer that contains walls
-        layer = ifcopenshell.api.run("layer.add_layer", model, Name="AI-WALL")
+        layer = ifcopenshell.api.run("layer.add_layer", model, name="AI-WALL")
 
         # And assign our wall representation item (in this example, there is
         # only one item) to the layer.

src/ifcopenshell-python/ifcopenshell/api/layer/edit_layer.py

@@ -36,7 +36,7 @@ def edit_layer(file: ifcopenshell.file, layer: ifcopenshell.entity_instance, att
 
     .. code:: python
 
-        layer = ifcopenshell.api.run("layer.add_layer", model, Name="AI-WALL")
+        layer = ifcopenshell.api.run("layer.add_layer", model, name="AI-WALL")
         ifcopenshell.api.run("layer.edit_layer", model,
             layer=layer, attributes={"Description": "All walls, based on the AIA standard."})
     """

src/ifcopenshell-python/ifcopenshell/api/layer/remove_layer.py

@@ -33,7 +33,7 @@ def remove_layer(file: ifcopenshell.file, layer: ifcopenshell.entity_instance) -
 
     .. code:: python
 
-        layer = ifcopenshell.api.run("layer.add_layer", model, Name="AI-WALL")
+        layer = ifcopenshell.api.run("layer.add_layer", model, name="AI-WALL")
         ifcopenshell.api.run("layer.remove_layer", model, layer=layer)
     """
     file.remove(layer)

src/ifcopenshell-python/ifcopenshell/api/layer/unassign_layer.py

@@ -56,7 +56,7 @@ def unassign_layer(
         ifcopenshell.api.run("geometry.edit_object_placement", model, product=wall)
 
         # Now let's create a layer that contains walls
-        layer = ifcopenshell.api.run("layer.add_layer", model, Name="AI-WALL")
+        layer = ifcopenshell.api.run("layer.add_layer", model, name="AI-WALL")
 
         # And assign our wall representation item (in this example, there is
         # only one item) to the layer.