Over-highlighting of heading's extra space

[kdeldycke]

Bug description

The space separating the Usage: header from the CLI name and argument schema is highlighted as if it was part of the heading.

To Reproduce

Given the following minimal Cloup CLI:

from cloup import HelpFormatter, HelpTheme, Context, command, Style, Color

SETTINGS = Context.settings(
    formatter_settings=HelpFormatter.settings(
        theme=HelpTheme(
            heading=Style(fg=Color.bright_blue, bold=True, underline=True),
        )
    )
)

@command(context_settings=SETTINGS)
def cli():
    pass

if __name__ == '__main__':
    cli()

If I run this with the latest version of Cloup, I get the following help screen:

Expected behavior

Instead, I expect the first line of the help screen renders like this:

Notice how the space after Usage: is not underlined.

I.e. the first line should not produce:

"\x1b[94m\x1b[1m\x1b[4mUsage: \x1b[0mcloup_heading_highlight.py [OPTIONS]"

But:

"\x1b[94m\x1b[1m\x1b[4mUsage:\x1b[0m cloup_heading_highlight.py [OPTIONS]"

[janluke]

Thanks for reporting!

[kdeldycke]

Thanks @janluke for the quick fix!