process: Backfill missing Version headers

…for BIPs that have a Changelog section that mentions a version.
BIP 1 and BIP 340 have Changelog sections, but do not define versions.

bip-0077.md

@@ -12,6 +12,7 @@
   Discussion: https://github.com/bitcoin/bips/pull/1483
               https://gnusha.org/pi/bitcoindev/7B11AE34-27A7-46ED-95BF-66CA13BA26F3@ngould.dev/#t
               https://gnusha.org/pi/bitcoindev/3C0A6E4C-444E-4E75-829C-1A21D8EE40E0@ngould.dev/#t
+  Version: 0.2.0
   Requires: 21, 78, 173, 174
 ```