docs(bip-0046): add Rationale section

Author: theborakompanioni

bip-0046.mediawiki

@@ -28,8 +28,6 @@ It would be useful to have a common derivation scheme so that users of wallet so
 
 We largely use the same approach used in BIPs 49, 84 and 86 for ease of implementation.
 
-This standard is already implemented and deployed in JoinMarket. As most changes would require a protocol change of a live system, there is limited scope for changing this standard in review. This BIP is more about documenting something which already exists, warts and all.
-
 It would be useful to be able to keep the private keys of fidelity bonds in cold storage. This would allow the sybil resistance of a system to increase without hot wallet risk.
 
 == Backwards Compatibility ==
@@ -54,10 +52,11 @@ To allow for holding fidelity bonds in cold storage, there is an intermediate ke
 
 Where the endpoint might be a IRC nickname or Tor onion hostname. The certificate keypair can be kept online and used to prove ownership of the fidelity bond. Even if the hot wallet private keys are stolen, the coins in the timelocked address will still be safe, although the thief will be able to impersonate the fidelity bond until the expiry.
 
-=== Fixed timelock values ===
+== Rationale ==
 
 It would be useful for the user to avoid having to keep a record of the timelocks in the time-locked addresses. So only a limited small set of timelocks are defined by this BIP. This way the user must only store their seed phrase, and knowledge that they have coins stored using this BIP standard. The user doesn't need to remember or store any dates.
 
+This standard is already implemented and deployed in JoinMarket. As most changes would require a protocol change of a live system, there is limited scope for changing this standard in review. This BIP is more about documenting something which already exists, warts and all.
 
 == Specifications ==