Update readme upgrade history

readme.md

@@ -39,9 +39,21 @@ Please also make sure to have a look to the [contributing guidelines](https://gi
 
 Information related to the Lum Network mainnet `lum-network-1` can be found in the [mainnet repository](https://github.com/lum-network/mainnet).
 
-### v1.6.4 - `TODO` - Block `TODO`
+### v1.6.7 - 2024-06-03 - Block 13241000
+CosmosMillions: Fix ICQ issues and improve error management.
 
-`TODO`
+[Upgrade guide here](https://github.com/lum-network/mainnet/blob/master/upgrades/v1.6.7/guide.md).
+
+### v1.6.6 - 2024-05-16 - Block 12969000
+Vulnerability patch related to the Cosmos SDk.
+CosmosMillions: Unlock HUAHUA Pool drawing procedure.
+
+[Upgrade guide here](https://github.com/lum-network/mainnet/blob/master/upgrades/v1.6.6/guide.md).
+
+### v1.6.5 - 2024-03-12 - Block 11992000
+CosmosMillions: Add Close Pool feature and improve deposit retry for ICA operations.
+
+[Upgrade guide here](https://github.com/lum-network/mainnet/blob/master/upgrades/v1.6.5/guide.md).
 
 ### v1.6.4 - 2024-02-01 - Block 11390000
 CosmosMillions: Make ICA channel restoration unlock all entities and revamp the fee system to allow for more than one fee taker.