Add CHANGELOG entry

CHANGELOG.md

@@ -5,6 +5,7 @@
 - [#3224](https://github.com/poanetwork/blockscout/pull/3224) - Top tokens page
 
 ### Fixes
+- [#3237](https://github.com/poanetwork/blockscout/pull/3237) - Refine contract method signature detection for read/write feature
 - [#3235](https://github.com/poanetwork/blockscout/pull/3235) - Fix coin supply api edpoint
 - [#3233](https://github.com/poanetwork/blockscout/pull/3233) - Fix for the contract verifiaction for solc 0.5 family with experimental features enabled
 - [#3231](https://github.com/poanetwork/blockscout/pull/3231) - Improve search: unlimited number of searching results