Merge bitcoin/bitcoin#25166: doc: Add link to NetBSD release

174f58c Add link to NetBSD release (Marnix)

Pull request description:

  For consistency with other Build Guides, like `doc/build-freebsd.md` & `doc/build-openbsd.md`

ACKs for top commit:
  theStack:
    Code-review ACK 174f58c
  vincenzopalazzo:
    ACK bitcoin/bitcoin@174f58c

Tree-SHA512: 08297aac82ee8fab2bbcb486b13b9c6ca12fb4fba573e9979e94204bd7340c2d13f1e54e07b314498603c291c25e29f2e89141ee150478951f699772538b709c

Author: fanquake

doc/build-netbsd.md

@@ -1,6 +1,6 @@
-NetBSD build guide
+NetBSD Build Guide
 ======================
-(updated for NetBSD 8.0)
+**Updated for NetBSD [8.0](https://www.netbsd.org/releases/formal-8/NetBSD-8.0.html)**
 
 This guide describes how to build bitcoind and command-line utilities on NetBSD.