pydoc HTML output is not responsive and has no viewport meta in released versions

python -m pydoc -w generates standalone HTML pages for modules. The output is not usable on mobile:

• The generated page has no tag in any released version (3.11-3.13). A viewport tag was added to the main branch only recently (Lib/pydoc.py), so it is not in any release yet.
• Lib/pydoc_data/_pydoc.css contains no layout media queries at all; the only @media block is prefers-color-scheme: dark. The navigation sidebar and content are laid out with fixed widths, which overflows on narrow screens.

Related: #127276 ("Missing styles for pages created by a 'python -m pydoc -w' call", open) and #153906 (closed). This issue is specifically about the mobile/responsive behavior.

Expected: backport/keep a viewport meta tag in the generated HTML and add a max-width media query that stacks the sidebar above the content on narrow screens.

Empieza con Lib/pydoc.py y Lib/pydoc_data/_pydoc.css, y luego ejecuta python -m pydoc -w sobre un módulo para inspeccionar la página generada. Se considera terminado cuando la salida publicada incluye la etiqueta meta de viewport y, en pantallas estrechas, la navegación se coloca encima del contenido sin desbordamiento.