docs: README update

Author: kevinmichaelchen

README.md

@@ -6,6 +6,44 @@ A TypeScript binding for the Common Expression Language (CEL) using [cel-rust](h
 
 [Common Expression Language (CEL)](https://github.com/google/cel-spec) is an expression language created by Google that implements common semantics for expression evaluation. It's a simple language for expressing boolean conditions, calculations, and variable substitutions. CEL is used in various Google products and open-source projects for policy enforcement, configuration validation, and business rule evaluation.
 
+## Usage
+
+See the full [language definition][lang-def] for a complete overview of CEL.
+
+[lang-def]: https://github.com/google/cel-spec/blob/master/doc/langdef.md
+
+```typescript
+import { CelProgram } from 'cel-typescript';
+
+// Basic string and numeric operations
+const program1 = await CelProgram.compile('size(message) > 5');
+await program1.execute({ message: 'Hello World' }); // true
+
+// Complex object traversal and comparison
+const program2 = await CelProgram.compile('user.age >= 18 && user.preferences.notifications');
+await program2.execute({
+  user: {
+    age: 25,
+    preferences: { notifications: true }
+  }
+}); // true
+
+// List operations and built-in functions
+const program3 = await CelProgram.compile('items.filter(i, i.price < 100).size() > 0');
+await program3.execute({
+  items: [
+    { name: 'Book', price: 15 },
+    { name: 'Laptop', price: 1000 }
+  ]
+}); // true
+
+// Date/time operations using timestamp() macro
+const program4 = await CelProgram.compile('timestamp(event_time) < timestamp("2025-01-01T00:00:00Z")');
+await program4.execute({
+  event_time: '2024-12-31T23:59:59Z'
+}); // true
+```
+
 ## Architecture
 
 This project consists of three main components:
@@ -43,19 +81,6 @@ The build process creates several important files:
 - `index.js`: The compiled JavaScript wrapper around the native module
 - `index.d.ts`: TypeScript type definitions generated from the Rust code
 
-## Usage
-
-```typescript
-import { CelProgram } from 'cel-typescript';
-
-// Compile a CEL expression
-const program = await CelProgram.compile('size(message) > 5');
-
-// Execute the expression with a context
-const result = await program.execute({ message: 'Hello World' });
-console.log(result); // true
-```
-
 ## Building
 
 ```bash