add nip14.GetSubject()

nip14/subject.go

@@ -0,0 +1,12 @@
+package nip14
+
+import "github.com/nbd-wtf/go-nostr"
+
+func GetSubject(tags nostr.Tags) string {
+	for _, tag := range tags {
+		if len(tag) >= 2 && tag[0] == "subject" {
+			return tag[1]
+		}
+	}
+	return ""
+}