BIP34: Add version header and changelog section

bip-0034.mediawiki

@@ -6,6 +6,7 @@
   Status: Deployed
   Type: Specification
   Assigned: 2012-07-06
+  Version: 1.0.3
 </pre>
 
 ==Abstract==
@@ -35,3 +36,10 @@ https://github.com/bitcoin/bitcoin/pull/1526
 ==Result==
 
 Block number 227,835 (timestamp 2013-03-24 15:49:13 GMT) was the last version 1 block.
+
+==Changelog==
+
+* 1.0.3: 2020-11-18: clarify that encoding must be minimal
+* 1.0.2: 2016-02-05: correction to format prediction regarding sign bit
+* 1.0.1: 2016-02-01: updated to Final, logged activation block
+* 1.0.0: 2012-07-06: proposed