Answer prose round 1: errNoData, the reads paragraph and the changelog entry read in one pass, the Library section shows the import block for one locale, and the decisions state why New checks no reads and which goal the embed serves

CHANGELOG.md

@@ -130,8 +130,9 @@ replacement, and each removed path, column or flag.
   `…/geo/US`. `data.Modules()`, from `github.com/larvit/fejkdata/data`, lists every one,
   and the CLI carries them all. `New` loads the modules `WithDataFS(modules...)` names and
   the folders `WithDataPath` names, and fails, naming `WithDataFS`, where no such option
-  is given; `WithDataFS()` loads none. A manifest's `reads` lists the modules its source
-  reads by default, and a reference naming nothing names them, or says there are none.
+  is given. A manifest's `reads` lists the modules its source reads by default, and a
+  reference to a path nothing provides fails, naming those modules or saying there are
+  none.
 - A data source whose root holds a `.fejkdata.json` manifest with an `index` loads each
   category on the first call reaching it, as each shipped module does. Data failing to load,
   in `New` or on that first call, gives an error matching `ErrLoad`, and the CLI exits 1.