feat(i18n): add template alias for numeric shorthand

Co-Authored-By: Virgil <virgil@lethean.io>

grammar.go

@@ -843,6 +843,7 @@ func TemplateFuncs() template.FuncMap {
 		"title":           Title,
 		"lower":           Lower,
 		"upper":           Upper,
+		"n":               N,
 		"past":            PastTense,
 		"gerund":          Gerund,
 		"plural":          Pluralize,

grammar_test.go

@@ -1001,6 +1001,7 @@ func TestTemplateFuncs(t *testing.T) {
 		"title",
 		"lower",
 		"upper",
+		"n",
 		"past",
 		"gerund",
 		"plural",
@@ -1089,6 +1090,31 @@ func TestTemplateFuncs_PromptAndLang(t *testing.T) {
 	}
 }
 
+func TestTemplateFuncs_NumericAlias(t *testing.T) {
+	svc, err := New()
+	if err != nil {
+		t.Fatalf("New() failed: %v", err)
+	}
+	SetDefault(svc)
+
+	tmpl, err := template.New("").Funcs(TemplateFuncs()).Parse(
+		`{{n "number" 1234567}}|{{n "ago" 3 "hours"}}`,
+	)
+	if err != nil {
+		t.Fatalf("Parse() failed: %v", err)
+	}
+
+	var buf strings.Builder
+	if err := tmpl.Execute(&buf, nil); err != nil {
+		t.Fatalf("Execute() failed: %v", err)
+	}
+
+	got := buf.String()
+	if !strings.HasPrefix(got, "1,234,567|3 hours ago") {
+		t.Fatalf("template numeric alias = %q, want prefix %q", got, "1,234,567|3 hours ago")
+	}
+}
+
 func TestTemplateFuncs_TimeHelpers(t *testing.T) {
 	svc, err := New()
 	if err != nil {