Parses an optional docgen.toml. When absent, SiteConfig::default()
reproduces docgen's pre-P6 hard-coded behaviour exactly, so a project with
no config builds identically to before.
Parses an optional docgen.toml. When absent, SiteConfig::default()
reproduces docgen's pre-P6 hard-coded behaviour exactly, so a project with
no config builds identically to before.