Consolidate add_row methods and other polish

Author: gregorgorjanc

RcppTskit/NEWS.md

@@ -4,7 +4,7 @@ All notable changes to `RcppTskit` are documented in this file.
 The file format is based on [Keep a Changelog](https://keepachangelog.com),
 and releases adhere to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.3.0] 2026-03-02
+## [0.3.0] 2026-04-07 (not yet released)
 
 ### Added (new features)
 
@@ -61,8 +61,8 @@ and releases adhere to [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 ### Maintenance
 
 - Turn vignette URL as hyperlinks and similar cosmetics.
-- State mirroring of the `R/Python` APIs and `C++/C` APIs across the package.
-- Update tskit C to 1.3.1
+- State that we mirror the `R/Python` APIs and `C++/C` APIs across the package.
+- Update `tskit C` to 1.3.1
 - TODO
 
 ## [0.2.0] - 2026-02-22