WoofWare.TimingWheel.0.7.3

Stop shipping raw <picture> tags in the NuGet readme (#20)

nuget.org renders a package readme with Markdig's DisableHtml(), which
removes the HTML block parser: raw HTML is not dropped but falls through
to a paragraph and is escaped. The <picture> element that gives GitHub its
light/dark logo therefore appears on the published package page as literal
tags today. Relative image paths are unsupported there in any case.

So pack a stripped copy from obj/ rather than README.md itself. GitHub
keeps the theme-aware logo; on nuget.org the logo is the PackageIcon,
which the sidebar renders against either theme.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>