Merge bitcoin/bitcoin#28189: doc: diversify network outbounds release note

7463d25 doc: Add release note (Amiti Uttarwar)

Pull request description:

  release notes for #27213

ACKs for top commit:
  mzumsande:
    ACK 7463d25

Tree-SHA512: 16c479774ed9242d8d044d08cc919550ccd07020423a3dcd99f07dad36e4dafd8243dc47f9f7f0c8eedcb53efd85ec65afedba56422452f637d313ec7c901520

Author: fanquake

doc/release-notes-27213.md

@@ -0,0 +1,8 @@
+P2P and network changes
+------
+
+- Nodes with multiple reachable networks will actively try to have at least one
+  outbound connection to each network. This improves individual resistance to
+  eclipse attacks and network level resistance to partition attacks. Users no
+  longer need to perform active measures to ensure being connected to multiple
+  enabled networks.