Add cf table reference (#236)

* Update accessor.py

* update url

Author: malmans2

cf_xarray/accessor.py

@@ -1532,7 +1532,7 @@ def add_canonical_attributes(
     ) -> Union[Dataset, DataArray]:
         """
         Add canonical CF attributes to variables with standard names.
-        Attributes are parsed from the official CF standard name table.
+        Attributes are parsed from the official CF standard name table [1]_.
         This function adds an entry to the "history" attribute.
 
         Parameters
@@ -1554,6 +1554,10 @@ def add_canonical_attributes(
         Notes
         -----
         The ``"units"`` attribute is never added to datetime-like variables.
+
+        References
+        ----------
+        .. [1] https://cfconventions.org/standard-names.html
         """
 
         # Arguments to add to history

doc/examples/introduction.ipynb

@@ -1007,7 +1007,7 @@
     "## Feature: Add canonical CF attributes\n",
     "\n",
     "`cf_xarray` can add missing canonical CF attributes consistent with the official\n",
-    "[CF standard name table](https://cfconventions.org/Data/cf-standard-names/77/build/cf-standard-name-table.html).\n"
+    "[CF standard name table](https://cfconventions.org/standard-names.html).\n"
    ]
   },
   {