Update CHANGELOG.md

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Current
 
 ### Features
+- [#2073](https://github.com/poanetwork/blockscout/pull/2073) - blockscout default theme
 - [#1963](https://github.com/poanetwork/blockscout/pull/1963), [#1959](https://github.com/poanetwork/blockscout/pull/1959), [#1948](https://github.com/poanetwork/blockscout/pull/1948), [#1936](https://github.com/poanetwork/blockscout/pull/1936), [#1925](https://github.com/poanetwork/blockscout/pull/1925), [#1922](https://github.com/poanetwork/blockscout/pull/1922), [#1903](https://github.com/poanetwork/blockscout/pull/1903), [#1874](https://github.com/poanetwork/blockscout/pull/1874), [#1895](https://github.com/poanetwork/blockscout/pull/1895), [#2031](https://github.com/poanetwork/blockscout/pull/2031) - added new themes and logos for poa, eth, rinkeby, goerli, ropsten, kovan, sokol, xdai, etc, rsk
 - [#2010](https://github.com/poanetwork/blockscout/pull/2010) - added "block not found" and "tx not found pages"
 - [#1928](https://github.com/poanetwork/blockscout/pull/1928) - pagination styles were updated