Fix AR labeling + core docstrings typo (#549)

Author: AlexAndorra

pymc_extras/statespace/models/structural/components/autoregressive.py

@@ -114,7 +114,7 @@ def populate_component_properties(self):
         if self.k_endog > 1:
             self.param_dims[f"params_{self.name}"] = (
                 f"endog_{self.name}",
-                AR_PARAM_DIM,
+                f"lag_{self.name}",
             )
             self.param_dims[f"sigma_{self.name}"] = (f"endog_{self.name}",)
 

pymc_extras/statespace/models/structural/core.py

@@ -362,7 +362,7 @@ def extract_components_from_idata(self, idata: xr.Dataset) -> xr.Dataset:
         Returns
         -------
         idata: Dataset
-            An Dataset object with hidden states transformed to represent only the "interpretable" subcomponents
+            A Dataset object with hidden states transformed to represent only the "interpretable" subcomponents
             of the structural model.
 
         Notes