add notes regarding nightly toolchain and locked deps to README

Author: Alrighttt

README.md

@@ -7,8 +7,13 @@
 - **V2 Transaction Builder**: Build Sia V2 transactions including SpendPolicy support
 - **Walletd Client**: Interact with the Sia network via a local or remote instance of [Walletd](https://github.com/SiaFoundation/walletd).
 
+## Requirements
+
+Rust nightly-2023-06-01 is the only officially supported toolchain. This was chosen to keep this library inline with Komodo DeFi Framework. Similarly, dependencies have been locked to explicit versions to align with Komodo DeFi Framework's dependency tree.
+
 ## Contact
 
 For any questions or suggestions, please open an issue on GitHub.
 
 This project is supported by a [Sia Foundation grant](https://forum.sia.tech/t/standard-grant-proposal-htlc-upgrade-for-sia-for-use-in-atomic-swaps/410/5).
+