doc(explorer): Add changelog entry.

Add information for next explorer release v3.8.3

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.8.3] - 2024-08-07
+
+-   Removed graphQL polling.
+
 ## [3.8.2] - 2024-07-19
 
 -   Removed configurations to communicate with subgraph hosted-services.
@@ -375,7 +379,8 @@ Staking Pools
 
 -   First release
 
-[unreleased]: https://github.com/cartesi/explorer/compare/v3.8.2...HEAD
+[unreleased]: https://github.com/cartesi/explorer/compare/v3.8.3...HEAD
+[3.8.3]: https://github.com/cartesi/explorer/compare/v3.8.3...v3.8.2
 [3.8.2]: https://github.com/cartesi/explorer/compare/v3.8.2...v3.8.1
 [3.8.1]: https://github.com/cartesi/explorer/compare/v3.8.1...v3.8.0
 [3.8.0]: https://github.com/cartesi/explorer/compare/v3.8.0...v3.7.1