Add test for specified width and fix two minor doc issues

doc/_docstrings/objects.Norm.ipynb

@@ -4,7 +4,11 @@
    "cell_type": "code",
    "execution_count": null,
    "id": "0bfee8b6-1e3e-499d-96ae-735a5c230b32",
-   "metadata": {},
+   "metadata": {
+    "tags": [
+     "hide"
+    ]
+   },
    "outputs": [],
    "source": [
     "import seaborn.objects as so\n",

seaborn/_core/plot.py

@@ -616,8 +616,8 @@ def scale(self, **scales: Scale) -> Plot:
             - A list of values, implying a :class:`Nominal` scale (e.g. `["b", "r"]`)
 
         For more explicit control, pass a scale spec object such as :class:`Continuous`
-        or :class:`Nominal`. Or use `None` to use an "identity" scale, which treats data
-        values as literally encoding visual properties.
+        or :class:`Nominal`. Or pass `None` to use an "identity" scale, which treats
+        data values as literally encoding visual properties.
 
         Examples
         --------

tests/_core/test_plot.py

@@ -788,6 +788,12 @@ def test_two_grouping_variables(self, long_df):
             long_df, m, data_vars, split_vars, split_cols, split_keys
         )
 
+    def test_specified_width(self, long_df):
+
+        m = MockMark()
+        Plot(long_df, x="x", y="y").add(m, width="z").plot()
+        assert_array_almost_equal(m.passed_data[0]["width"], long_df["z"])
+
     def test_facets_no_subgroups(self, long_df):
 
         split_var = "col"