a few minor fixes

src/pystencilssfg/configuration.py

@@ -10,7 +10,8 @@ They take precedence in the following way:
 
  - Project configuration overrides the default configuration
  - Command line arguments override the project configuration
- - User configuration overrides all, but must not conflict with command-line arguments; otherwise, an error is thrown.
+ - User configuration overrides default and project configuration,
+   and must not conflict with command-line arguments; otherwise, an error is thrown.
 
 ### Project Configuration via Configurator Script
 
@@ -21,7 +22,10 @@ A configurator module is a Python file defining the following function at the to
 from pystencilssfg import SfgConfiguration
 
 def sfg_config() -> SfgConfiguration:
-    ...
+    # ...
+    return SfgConfiguration(
+        # ...
+    )
 ```
 
 The configuration module is passed to the code generation script via the command-line argument

src/pystencilssfg/source_components.py

@@ -232,7 +232,7 @@ class SfgMemberVariable(SrcObject, SfgClassMember):
         self,
         name: str,
         type: SrcType,
-        visibility: SfgVisibility = SfgVisibility.DEFAULT,
+        visibility: SfgVisibility = SfgVisibility.PRIVATE,
     ):
         SrcObject.__init__(self, type, name)
         SfgClassMember.__init__(self, visibility)
@@ -243,7 +243,7 @@ class SfgMethod(SfgFunction, SfgClassMember):
         self,
         name: str,
         tree: SfgCallTreeNode,
-        visibility: SfgVisibility = SfgVisibility.DEFAULT,
+        visibility: SfgVisibility = SfgVisibility.PUBLIC,
     ):
         SfgFunction.__init__(self, name, tree)
         SfgClassMember.__init__(self, visibility)
@@ -255,7 +255,7 @@ class SfgConstructor(SfgClassMember):
         parameters: Sequence[SrcObject] = (),
         initializers: Sequence[str] = (),
         body: str = "",
-        visibility: SfgVisibility = SfgVisibility.DEFAULT,
+        visibility: SfgVisibility = SfgVisibility.PUBLIC,
     ):
         SfgClassMember.__init__(self, visibility)
         self._parameters = tuple(parameters)