docs: add README.md to bolt-lang crate

crates/bolt-lang/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "bolt-lang"
 description = "Bolt Language"
+readme = "README.md"
 version = { workspace = true }
 authors = { workspace = true }
 repository = { workspace = true }

crates/bolt-lang/README.md

@@ -0,0 +1,84 @@
+# bolt-lang
+
+Rust primitives for building fully on-chain games and autonomous worlds on Solana using the [Bolt](https://github.com/magicblock-labs/bolt) framework.
+
+## Overview
+
+`bolt-lang` is the core library for the Bolt Entity Component System (ECS) framework. It provides macros and types for defining **components** (data) and **systems** (logic) that run on the Solana blockchain.
+
+## Features
+
+- **`#[component]`** -- Define on-chain data components with automatic PDA derivation and serialization.
+- **`#[system]`** -- Define systems that operate on components, enforced through CPI.
+- **`#[system_input]`** -- Declare which components a system reads and writes.
+- **`#[arguments]`** -- Define typed arguments passed to systems at runtime.
+- **`#[bolt_program]`** -- Annotate Anchor programs to integrate with the Bolt world.
+- **`#[delegate]`** -- Enable account delegation for transaction acceleration via MagicBlock's ephemeral rollups.
+- **Session keys** -- Re-exported from `session-keys` for gasless player interactions.
+
+## Installation
+
+Add `bolt-lang` to your `Cargo.toml`:
+
+```toml
+[dependencies]
+bolt-lang = "0.2"
+```
+
+Or use the Bolt CLI to scaffold a new project:
+
+```bash
+bolt init my-project
+```
+
+## Quick Example
+
+Define a component:
+
+```rust
+use bolt_lang::*;
+
+#[component]
+pub struct Position {
+    pub x: i64,
+    pub y: i64,
+    pub z: i64,
+}
+```
+
+Define a system:
+
+```rust
+use bolt_lang::*;
+
+#[system]
+pub mod movement {
+    pub fn execute(ctx: Context<Components>, args: Args) -> Result<Components> {
+        let position = &mut ctx.accounts.position;
+        position.x += args.dx;
+        position.y += args.dy;
+        Ok(ctx.accounts)
+    }
+
+    #[system_input]
+    pub struct Components {
+        pub position: Position,
+    }
+
+    #[arguments]
+    pub struct Args {
+        pub dx: i64,
+        pub dy: i64,
+    }
+}
+```
+
+## Documentation
+
+- [Bolt Book](https://book.boltengine.gg) -- Tutorials and guides
+- [API Reference](https://docs.rs/bolt-lang) -- Generated API documentation
+- [MagicBlock Docs](https://docs.magicblock.gg) -- Platform documentation
+
+## License
+
+MIT