Add readme

Author: febo

programs/system/Cargo.toml

@@ -3,6 +3,9 @@ name = "pinocchio-system"
 description = "Pinocchio helpers to invoke System program instructions"
 version = "0.0.0"
 edition = "2021"
+license = "Apache-2.0"
+readme = "./README.md"
+repository = "https://github.com/febo/pinocchio"
 
 [dependencies]
 pinocchio = { version="^0", path="../../sdk/pinocchio" }

programs/system/README.md

@@ -0,0 +1,38 @@
+# `system`
+
+[`pinocchio`](https://crates.io/crates/pinocchio) helpers to perform cross-program invocations (CPIs) for System program instructions.
+
+Each instruction defines an `struct` with the accounts and parameters required. Once all values are set, you can call directly `invoke` or `invoke_signed` to perform the CPI.
+
+> [!IMPORTANT]
+> The API defined in this crate should be considered experimental.
+
+## Examples
+
+Creating a new account:
+```rust
+// This example assumes that the instruction receives a writable signer `payer_info`
+// and `new_account` accounts.
+CreateAccount {
+    from: payer_info,
+    to: new_account,
+    lamports: 1_000_000_000, // 1 SOL
+    space: 200,              // 200 bytes
+    owner: &spl_token::ID,
+}.invoke()?;
+```
+
+Performing a transfer of lamports:
+```rust
+// This example assumes that the instruction receives a writable signer `payer_info`
+// account and a writable `recipient` account.
+Transfer {
+    from: payer_info,
+    to: recipient,
+    lamports: 500_000_000, // 0.5 SOL
+}.invoke()?;
+```
+
+## License
+
+The code is licensed under the [Apache License Version 2.0](../LICENSE)