v0.10.0

Added

• Preserved the raw format fragment for display-only placeholders, exposing it
  through TemplateFormatter::display_spec()/format_fragment() so derived
  implementations can forward :>8, :.3, and similar specifiers to
  write!.

Changed

• TemplateFormatter now owns display specs and TemplatePlaceholder::formatter
  returns a reference to reflect the richer formatter representation.

Tests

• Added a trybuild pass case and runtime assertions covering display alignment,
  precision, and fill specifiers to prevent regressions.

Documentation

• Documented the new display formatter support in the README (including the
  Russian translation) with examples showing how to recover preserved specs.