chore: add minimal SECURITY.md (nodejs#2560)

Trott · web-flow · commit c2a185056e2e · 2021-11-27T16:00:28.000-08:00
diff --git a/SECURITY.md b/SECURITY.md
@@ -0,0 +1,2 @@
+If you believe you have found a security issue in the software in this
+repository, please consult https://github.com/nodejs/node/blob/HEAD/SECURITY.md.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+If you believe you have found a security issue in the software in this`
	`2`	`+repository, please consult https://github.com/nodejs/node/blob/HEAD/SECURITY.md.`