Add "Under the Hood of the Neon Web3 Proxy" explanation to DOCS

[theDefiBat]

need to add an explanation on how an N-trx is converted into Multiple S-trxes
can pick some of the explanation and Image from here https://neonlabsorg.medium.com/neon-web3-proxy-facilitating-seamless-transactions-on-neon-evm-b33c2041aa08

It was difficult for me to understand how proxy was working internally while reading the Docs until I read the above medium article, so I created this issue...