add comment about address and private key version to html
add comment about address and private key version to html

jamescarter-le/brainwallet.github.io,rexquigg/brainwallet,jamescarter-le/brainwallet.github.io,sipak/brainwallet,Colored-Coins/brainwallet.github.io,2XL/brainwallet.github.io,Taiiwo/bitcoin-signature-tool,jhoenicke/brainwallet.github.io,A-Zak/brainwallet.github.io,btcspry/brainwallet.github.io,btcspry/brainwallet.github.io,brainwallet/brainwallet.github.io,nvoron23/brainwallet.github.io,A-Zak/brainwallet.github.io,sipak/brainwallet,brainwalletX/brainwalletX.github.io,nvoron23/brainwallet.github.io,jhoenicke/brainwallet.github.io,2XL/brainwallet.github.io,brainwalletX/brainwalletX.github.io,Colored-Coins/brainwallet.github.io,Taiiwo/bitcoin-signature-tool