Revert "Add RBF FAQ"
Revert "Add RBF FAQ"

This reverts commit b67bdf94620ba6528f3863193b7bcabc8029f3aa.

bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,btcdrak/bitcoincore.org,bitcoin-core/bitcoincore.org,bitcoin-core/bitcoincore.org,btcdrak/bitcoincore.org,btcdrak/bitcoincore.org