Update release notes

Author: mboben

README.md

@@ -7,6 +7,7 @@ go-flare is a modified version of [avalanchego@v1.10.0](https://github.com/ava-l
 - **Songbird: May 6, 2025 at 12 UTC**
 - **Flare: May 13, 2025 at 12 UTC**
 
+See [release notes](./RELEASES-flare.md) for more info.
 
 
 ## System Requirements

RELEASES-flare.md

@@ -2,7 +2,7 @@
 
 Here are listed specific changes to the code for the Flare and Songbird networks. For a comprehensive list of general changes, see [here](./avalanchego/RELEASES.md) for the AvalancheGo project and [here](./coreth/RELEASES.md) for the Coreth project.
 
-## [v1.10.0]
+## v1.10.0
 
 The changes go into effect on May 6, 2025 at 12 PM UTC for the Songbird network and on May 13, 2025 at 12 PM UTC for the Flare network.
 
@@ -14,7 +14,11 @@ The changes go into effect on May 6, 2025 at 12 PM UTC for the Songbird network
 
 - Reduce the target gas (for the 10-second rolling window used for dynamic fee calculation) to 15,000,000 from 150,000,000 for the Songbird network to be consistent with the Flare network.
 
-## [v1.9.0]
+### Note:
+
+- We recommend using `AddPermissionlessValidatorTx` and `AddPermissionlessDelegatorTx` transactions for adding validators and delegators after the fork. When creating `AddPermissionlessValidatorTx` you need to specify the BLS proof of posession (BLS public key and signature). You can find the BLS proof of posession in the response of `info.getNodeID` API. Path to the BLS private key is specified with `--staking-signer-key-file`. The default is `~/.avalanchego/staking/signer.key`. If it does not exist, it will be populated with a new key. You should copy it to your persistent storage along with the existing `staker.crt` and `staker.key` files.
+
+## v1.9.0
 
 ### Specific changes: