Update readme

README.md

@@ -1,3 +1,28 @@
 # PineVM
 
-Parser for the PineScript language.
+A modular PineScript interpreter written in Rust.
+
+PineVM executes PineScript code (TradingView's scripting language) with support for technical analysis, custom indicators, and strategy backtesting. The interpreter is designed to be extensible - you can add custom builtin functions and output types to integrate with your own systems.
+
+## Features
+
+- Full PineScript v5 language support
+- Technical analysis functions (moving averages, oscillators, etc.)
+- Drawing objects (plots, labels, boxes)
+- Modular output system - extend with [custom types and builtins](examples/custom-builtin-func)
+- Type-safe generic architecture
+
+## Example
+
+```rust
+use pine::Script;
+
+let script = Script::compile(r#"
+    fast_ma = ta.sma(close, 10)
+    slow_ma = ta.sma(close, 20)
+    plot(fast_ma, color=color.blue)
+    plot(slow_ma, color=color.red)
+"#)?;
+
+let output = script.execute(&bar)?;
+```