Fix broken BIP 3 reference in bip-0347 and bip-0360 changelogs

Both BIPs added a changelog entry on 2026-01-23 referencing the updated
BIP Process meta-BIP with the wrong form:

- bip-0360.mediawiki:404 rendered `[[bip-0003.mediawiki|BIP 003]]`, but
  the actual file is `bip-0003.md`. The MediaWiki link therefore failed
  to resolve to the BIP 3 page on the bitcoin/bips GitHub wiki render
  and on the bips.dev / bip339 style mirrors — readers of the bip-0360
  changelog landed on a 404.

- bip-0347.mediawiki:170 wrote the same reference as bare text
  `BIP 003` with no link at all, so readers of bip-0347 had no way to
  navigate to the BIP 3 they were meant to follow.

Rewrite both entries to use the canonical form `[[bip-0003.md|BIP 3]]`:

- `bip-0003.md` matches the actual filename.
- `BIP 3` matches the display text convention the README (line 40) and
  every other BIP in this repository already use when linking to
  bip-0003 — "BIP 003" with the three-digit zero-pad appears nowhere
  else in the repo for any BIP and is not part of the display style
  described in BIP 2.

Also drops the trailing whitespace on the bip-0347 line while we are
there (the `typos` CI tolerates it but it is inconsistent with every
other line in the same changelog block).

bip-0347.mediawiki

@@ -167,7 +167,7 @@ A full test suite with additional vectors can be found at the Bitcoin [https://g
 ==Changelog==
 
 * __1.0.0__ (2026-03-01) - Marked as complete.
-* __0.3.1__ (2026-01-23) - Made compliant with BIP 003, use cases added. 
+* __0.3.1__ (2026-01-23) - Made compliant with [[bip-0003.md|BIP 3]], use cases added.
 * __0.3.0__ (2024-05-06) - Merged to BIP repo
 * __0.2.0__ (2024-04-24) - Assigned BIP number
 * __0.1.0__ (2023-12-11) - Initial draft posted