Merge pull request ethereum#5622 from feliche93/gas_fees_calculator

Add gas fees calculator resource [fixes ethereum#5099]

src/content/developers/docs/gas/index.md

@@ -162,6 +162,7 @@ If you want to monitor gas prices, so you can send your ETH for less, you can us
 - [Blocknative ETH Gas Estimator](https://chrome.google.com/webstore/detail/blocknative-eth-gas-estim/ablbagjepecncofimgjmdpnhnfjiecfm) _Gas estimating Chrome extension supporting both Type 0 legacy transactions and Type 2 EIP-1559 transactions._
 
 - [ETH Gas Station](https://ethgasstation.info/) _Consumer oriented metrics for the Ethereum gas market_
+- [Cryptoneur Gas Fees Calculator](https://www.cryptoneur.xyz/gas-fees-calculator) _Calculate gas fees in your local currency for different transaction types on Mainnet, Arbitrum, and Polygon._
 
 ## Related tools {#related-tools}