docs: solution to support atomic instructions (nervosnetwork#112)

README.md

@@ -42,3 +42,15 @@ default_alloc!(4 * 1024, 516 * 1024, 64)
 Check `examples` and [tests](https://github.com/nervosnetwork/ckb-std/blob/master/contracts/ckb-std-tests) to learn how to use.
 
 See also [ckb-tool](https://github.com/nervosnetwork/capsule/tree/develop/crates/testtool) which helps you write tests.
+
+
+### Upgrading Issues
+
+Starting from ckb-std 0.16.0, RISC-V atomic instructions are generated by
+default. However, ckb-vm doesn't directly support atomic instructions. To
+address this, ckb-std provides the following solutions:
+
+1. Use the "dummy-atomic" feature (enabled by default)
+2. Adjust Rust compilation flags by adding `-C target-feature=-a` to `RUSTFLAGS`
+
+For more detailed information on compilation flags, refer to the [CKB Script Templates repository](https://github.com/cryptape/ckb-script-templates/tree/main?tab=readme-ov-file#molecule-uses-bytes-crates).