solang-parser README.md should mention breaking changes may occur

Signed-off-by: Samuel Moelius <sam@moeli.us>

solang-parser/README.md

@@ -1,4 +1,3 @@
-
 # Hyperledger Solang Solidity parser
 
 This crate is part of [Hyperledger Solang](https://solang.readthedocs.io/). It contains the
@@ -6,6 +5,8 @@ parser for Solidity, including the dialects used by Solang for Solana and Substr
 
 This parser is compatible with Ethereum Solidity v0.8.19.
 
+`solang-parser` is still `0.*.*`, so breaking changes [may occur at any time](https://semver.org/#spec-item-4). If you must depend on `solang-parser`, we recommend pinning to a specific version, i.e., `=0.y.z`.
+
 ```rust
 use solang_parser::{pt::{SourceUnitPart, ContractPart}, parse};