docs: update README for v0.3.0

Added "What's New in v0.3" section covering species, concepts,
sub_concepts, concept_comparison, template species inheritance,
and life arc field requirements. Updated quick start example
with v0.3 syntax including species and type system declarations.

docs/README.md

@@ -25,7 +25,8 @@ Storybook is a **compiled simulation language** designed for **open-world, auton
 Storybook defines characters, behaviors, relationships, and narrative events for autonomous agents in dynamic worlds. It bridges the gap between storytelling and technical simulation through:
 
 - **Readable syntax** - Code that looks like natural descriptions, but compiles to efficient bytecode
-- **Named nodes** - Behavior trees you can read as stories, that drive AI decision-making
+- **Type system** - Species, concepts, and sub-concepts for compile-time validation
+- **Behavior trees** - Named nodes you can read as stories, that drive AI decision-making
 - **Prose blocks** - Embed narrative directly in definitions for context-aware storytelling
 - **Rich semantics** - From simple traits to complex state machines and schedules
 - **Game engine integration** - Designed to power autonomous NPCs in Unity, Unreal, Godot, and custom engines
@@ -44,24 +45,56 @@ Storybook defines characters, behaviors, relationships, and narrative events for
 
 **Want inspiration?** Browse the [Examples Gallery](examples/24-baker-family-complete.md) to see what's possible!
 
+## What's New in v0.3
+
+Storybook v0.3 introduces a **compile-time type system** for stronger validation and richer world modeling:
+
+- **`species`** - Define base archetypes with default fields that characters inherit
+- **`concept` / `sub_concept`** - Algebraic data types with dot notation (`sub_concept Cup.Size { Small, Medium, Large }`)
+- **`concept_comparison`** - Compile-time pattern matching over concept variants
+- **Template species inheritance** - Templates extend species for layered defaults (`template Person: Human { ... }`)
+- **Life arc field requirements** - `life_arc Career requires { skill: Number }` validates fields at compile time
+
+v0.3 is a clean break from v0.2. See the [Type System reference](TYPE-SYSTEM.md) for full details.
+
 ## Quick Start
 
 ```storybook
-character Martha {
-    age: 34
-    skill_level: 0.95
+// Define a species with default fields
+species Human {
+    age: 0
+    energy: 0.5
+    mood: 0.5
+}
 
-    ---description
+// Template inheriting from species
+template Baker: Human {
+    baking_skill: 0.0..1.0
+    specialty: "bread"
+}
+
+// Character from template
+character Martha from Baker {
+    age: 34
+    baking_skill: 0.9
+    specialty: "sourdough"
+
+    ---backstory
     A master baker who learned from her grandmother
     and now runs the most popular bakery in town.
     ---
 }
 
-behavior Baker_MorningRoutine {
+// Type-safe concepts
+concept BakedGood
+sub_concept BakedGood.Category { Bread, Pastry, Cake }
+
+// Behavior trees
+behavior BakingWork {
     choose daily_priority {
-        then prepare_sourdough { ... }
-        then serve_customers { ... }
-        then restock_display { ... }
+        then prepare_sourdough
+        then serve_customers
+        then restock_display
     }
 }
 ```