tippy-header class only added to the first header in tip excerpt

[NamelessIV]

We want to change the font size of the different headers in the tips but only the first header of the excerpt has the tippy-header class added to it.

The cause appears to be in the _get_header_html() function line 470

                output += _get_header_html(sub_header, False)

In its context:

def _get_header_html(header: Tag | NavigableString, _start: bool = True) -> str:
    """Get the HTML for a header tag, including itself and some following content."""
    if not _start or not isinstance(header, Tag):
        output = str(header)
    else:
        header_copy = header.__copy__()
        header_copy["style"] = "margin-top: 0;"
        # add a class
        if "class" in header_copy.attrs:
            header_copy["class"].append("tippy-header")  # type: ignore[union-attr]
        else:
            header_copy["class"] = ["tippy-header"]
        output = str(header_copy)
    for sibling in header.next_siblings:
        if not isinstance(sibling, Tag):
            continue
        if sibling.name == "section":
            if sub_header := sibling.find(["h1", "h2", "h3", "h4", "h5", "h6"]):
                output += _get_header_html(sub_header, False)
            break
        if sibling.name == "p":
            output += str(sibling)
            if (next_sibling := next_sibling_tag(sibling)) and next_sibling.name == "p":
                output += str(next_sibling)
            break
    return output

If the False is replaced by True the tippy-header class is added to each header level.

Line 470 becomes:

                output += _get_header_html(sub_header, True)

Where in the source file: https://github.com/sphinx-extensions2/sphinx-tippy/blob/17770ce8f641b844f83d09624a388cdfca374531/src/sphinx_tippy.py#L452C5-L477C21