update contract-addresses.mdx (#357)

Author: cctdaniel

pages/price-feeds/contract-addresses.mdx

@@ -6,6 +6,7 @@ The contracts are split by ecosystem into several different documents:
 - [EVM](contract-addresses/evm)
 - [Solana](contract-addresses/solana)
 - [Starknet](contract-addresses/starknet)
+- [Fuel](contract-addresses/fuel)
 - [Aptos](contract-addresses/aptos)
 - [Sui](contract-addresses/sui)
 - [CosmWasm](contract-addresses/cosmwasm)