closes#1832
The shred map (xref) builder was issuing warnings. This fix includes
- Adjustments to the shredder map builder itself so that it
understands, e.g., app-project relative example paths.
- `**/guide/glossary.jade` now (Jade) `includes` the shared parent
`glossary.jade` rather than (Harp) importing (via `partial`). This
fixes `makeExample` path issues in the glossary.
- Adjusted some `makeExample` paths that were ok for site build, but
confused the xref tool.
closes#1818
Previously, the markdown of some chapters was converted to Jade markup
to support the conditional exclusion of TS prose parts in Dart
chapters. This commit reverts some of that back to clean markdown,
thanks to a few custom directives.