_content/doc/go1.27: add release notes for net/http.Server.MaxHeaderValueCount

Fixes golang/go#79936

Change-Id: I6a05796b8b6045d9af462ad60d6c4df66a6a6964
Reviewed-on: https://go-review.googlesource.com/c/website/+/797200
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Nicholas Husin <husin@google.com>

_content/doc/go1.27.md

diff --git a/_content/doc/go1.27.md b/_content/doc/go1.27.md
index 202f16f..f19b961 100644
--- a/_content/doc/go1.27.md
+++ b/_content/doc/go1.27.md
@@ -580,6 +580,14 @@
 or usage of [`Transport`](/pkg/net/http#Transport) or [`Client`](/pkg/net/http#Client) in the first place, and a deeper look would
 likely be beneficial.
 
+<!-- go.dev/issue/79936 -->
+
+The new [`Server.MaxHeaderValueCount`](/pkg/net/http#Server.MaxHeaderValueCount)
+field allows HTTP servers to control the number of header values that they are
+willing to accept. If unset,
+[`DefaultMaxHeaderValueCount`](/pkg/net/http#DefaultMaxHeaderValueCount) is
+used.
+
 #### [`net/http/httptest`](/pkg/net/http/httptest/)
 
 <!-- 6-stdlib/99-minor/net/http/httptest/76608.md -->