feat: add alias reference_conditions for X and reference_observations…

… for y

src/autora/state.py

@@ -1506,6 +1506,13 @@ def X(self) -> pd.DataFrame:
             return pd.DataFrame()
         return self.experiment_data[self.iv_names]
 
+    @property
+    def reference_conditions(self) -> pd.DataFrame:
+        """
+        Returns the already observed conditions as a pd.DataFrame.
+        """
+        return self.X
+
     @property
     def y(self) -> pd.DataFrame:
         """
@@ -1533,6 +1540,13 @@ def y(self) -> pd.DataFrame:
             return pd.DataFrame()
         return self.experiment_data[self.dv_names]
 
+    @property
+    def reference_observations(self) -> pd.DataFrame:
+        """
+        Returns the observations as a pd.DataFrame
+        """
+        return self.y
+
     @property
     def model(self):
         if len(self.models) == 0: