Amend the RFC to match what shipped in 2.0.0rc1

Two reconciliations before merging the RFC as the standing design
record. The design did not drift -- it grew after this doc froze on
2026-07-11 -- so nothing here contradicted the release; it was missing
a field and carried an illustrative string that never matched output.

- Add the `maiden` field (#274), decided after the RFC was written: a
  birth surname introduced by a marker like née/geb. that v1 folded
  into middle/last. It is the one user-facing 2.0 field the document
  omitted.
- Fix the ambiguity example's detail text to the actual shipped string
  ("leading 'Van' may be a family-name particle; read as a given
  name"). Detail text is not stable API, but an example that does not
  reproduce is a wart in a standing record.

Verified every other code example in the RFC runs verbatim against
2.0.0rc1 -- replace(), the Token repr, the FAMILY_FIRST example, the RU
locale, and the "not in 2.0" claim for parse_all()/explain().

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: derek73

docs/design/nameparser-2.0-rfc.md

@@ -131,6 +131,8 @@ the standards world already uses (HTML autocomplete
 - `title` and `suffix` **stay** — they have ecosystem gravity, and the
   positional taxonomy ("pre-nominal"/"post-nominal") is documented
   rather than spelled into identifiers.
+- `maiden` is a **new** field — a birth surname introduced by a marker
+  like `née` or `geb.`, which v1 folded into `middle`/`last` (#274).
 
 `HumanName` keeps every v1 spelling, including `string_format` keys, so
 existing code is unaffected; only new-API adopters see the new names.
@@ -176,8 +178,8 @@ reading **and says so**:
 
 ```python
 parse("Van Johnson").ambiguities
-# (Ambiguity(PARTICLE_OR_GIVEN, "leading 'van' can be a particle or a
-#   given name; chose given", tokens=(...)),)
+# (Ambiguity(PARTICLE_OR_GIVEN, "leading 'Van' may be a family-name
+#   particle; read as a given name", tokens=(...)),)
 ```
 
 `Ambiguity.kind` values are stable API you can filter on. This is also