[Feature Request] Print PDF's in landscape orientation and using specific page size

[cjlotz]

How difficult will it be to extend to the existing PDF printing logic to specify the orientation and page size of the page that should be used? Thinking of adding pdfOrientation: landscape | portrait setting. If not specified it should default to portrait. For size, using something like pdfPageSize: A0 | A1 .. | Letter

If possible, any pointers where to start looking at adding the support to the existing code base?

[filzrev]

I've confirmed it can change page size and orientation with following steps.

1. Set PagePdfOptions's PreferCSSPageSize property to true.

docfx/src/Docfx.App/PdfBuilder.cs

Line 169 in 464b947

return await page.PdfAsync(new PagePdfOptions { PrintBackground = outline.pdfPrintBackground });

See: https://playwright.dev/docs/api/class-page#page-pdf-option-prefer-css-page-size

2. Add print style at custom template's main.css file.

@media print {
  @page {
    size: A3 landscape
  }
}

[yufeih]

Make sense to me to set PreferCSSPageSize to true.