Adds post history, fixes created date

Author: EthanHeilman

bip-0347.mediawiki

@@ -7,8 +7,9 @@
   Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0347
   Status: Draft
   Type: Standards Track
-  Created: 2023-10-21
+  Created: 2023-12-11
   License: BSD-3-Clause
+  Post-History: 2023-10-21: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2023-October/022049.html [bitcoin-dev] Proposed BIP for OP_CAT
 </pre>
 
 ==Abstract==