add docstring

Author: juleswg23

docs/styles.css

@@ -2,7 +2,7 @@
     --bs-body-bg: white;
 }
 
-.sidebar {
+.sidebar-navigation {
     background-color: white !important;
 }
 

gt_extras/styling.py

@@ -11,13 +11,90 @@
 def gt_add_divider(
     gt: GT,
     columns: SelectExpr,
-    sides: Literal["right", "left", "top", "bottom", "all"]
-    | list[Literal["right", "left", "top", "bottom", "all"]] = "right",
+    sides: (
+        Literal["right", "left", "top", "bottom", "all"]
+        | list[Literal["right", "left", "top", "bottom", "all"]]
+    ) = "right",
     color: str = "grey",
     divider_style: Literal["solid", "dashed", "dotted", "hidden", "double"] = "solid",
     weight: int = 2,
     include_labels: bool = True,
 ) -> GT:
+    """
+    Add dividers to specified columns in a GT table.
+
+    The `gt_add_divider()` function takes an existing `GT` object and adds dividers to the specified
+    columns. Dividers can be applied to one or more sides of the cells, with customizable color,
+    style, and weight. Optionally, dividers can also be applied to column labels.
+
+    Parameters
+    ----------
+    gt
+        A `GT` object to modify.
+
+    columns
+        The columns to which dividers should be applied.
+
+    sides
+        The sides of the cells where dividers should be added. Options include `"right"`, `"left"`,
+        `"top"`, `"bottom"`, or `"all"`. A list of sides can also be provided to apply dividers to
+        multiple sides.
+
+    color
+        The color of the dividers.
+
+    divider_style
+        The style of the dividers. Options include `"solid"`, `"dashed"`, `"dotted"`, `"hidden"`,
+        and `"double"`.
+
+    weight
+        The thickness of the dividers in pixels.
+
+    include_labels
+        Whether to include dividers in the column labels. If `True`, dividers will be applied to
+        both the body and the column labels. If `False`, dividers will only be applied to the body.
+
+    Returns
+    -------
+    GT
+        A `GT` object with dividers added to the specified columns.
+
+    Examples
+    --------
+    ```{python}
+    import pandas as pd
+    from great_tables import GT
+    from great_tables.data import peeps
+    import gt_extras as gte
+
+    peeps_mini = peeps.head(6)
+
+    gt = (
+        GT(peeps_mini)
+        .cols_hide([
+            "name_family", "postcode", "country", "country_code",
+            "dob", "gender", "state_prov", "email_addr",
+        ])
+        .tab_spanner("Location", ["address", "city"])
+        .tab_spanner("Body Measurements", ["height_cm", "weight_kg"])
+    )
+
+    gt.pipe(
+        gte.gt_add_divider,
+        columns="name_given",
+        color="#FFB90F",
+        divider_style="double",
+        weight=8,
+    ).pipe(
+        gte.gt_add_divider,
+        columns="phone_number",
+        color="purple",
+        sides=["right", "left"],
+        weight=5,
+    )
+    ```
+    """
+
     locations = [loc.body(columns=columns)]
 
     if include_labels: