fix: repair dead links (whitepaper, API host, junk links) - #16

Fixes broken links found by link check (all pre-verified 404):

1. get-started/whitepaper.md

   • https://github.com/minswap/docs/raw/master/.gitbook/assets/whitepaper-dutch.pdf — 404 (file does not exist in repo)
   • https://github.com/minswap/docs/raw/master/.gitbook/assets/whitepaper-cn.pdf — 404 (file does not exist in repo)
   • Replaced both bullets with the Spanish version, which does exist:
     https://github.com/minswap/docs/raw/master/.gitbook/assets/whitepaper-es.pdf — verified HTTP 200

2. governance/governance-module.md

   • Two occurrences of a junk https://r.search.yahoo.com/... redirect (whose own RU= param shows it just points at forum.minswap.org)
   • Replaced with the direct link: https://forum.minswap.org/ — verified HTTP 200

Not changed (verified, no fix needed):

• https://api-mainnet-prod.minswap.org/v1/assets?term=&limit=1 in developer/minswap-apis.md currently returns HTTP 200 from this machine, so the API host is left as-is.