Mathics -> Mathics3 (#1800)

A couple more places where Mathics -> Mathics3

Author: rocky

mathics/core/evaluation.py

@@ -641,7 +641,7 @@ def get_data(self):
 
 class Output(ABC):
     """
-    Base class for Mathics output history.
+    Base class for Mathics3 output history.
     This needs to be subclassed.
     """
 

mathics/core/load_builtin.py

@@ -183,7 +183,7 @@ def get_submodule_names(obj) -> list:
     So in this example then, in the list the modules returned for
     Python module `mathics.builtin.colors` would be the
     `mathics.builtin.colors.named_colors` module which contains the
-    definition and docs for the "Named Colors" Mathics Builtin
+    definition and docs for the "Named Colors" Mathics3 Builtin
     Functions.
     """
     modpkgs = []