i18n: expose the LoaderConfig from the main i18n instance and add an example

Signed-off-by: Gerasimos (Makis) Maropoulos <kataras2006@hotmail.com>

_examples/i18n/i18n-template/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+
+	// go get -u github.com/gertd/go-pluralize
+	"github.com/gertd/go-pluralize"
+)
+
+func main() {
+	app := newApp()
+	app.Listen(":8080")
+}
+
+func newApp() *iris.Application {
+	app := iris.New()
+
+	pluralize := pluralize.NewClient()
+	app.I18n.Loader.FuncMap = map[string]interface{}{
+		"plural": func(word string, count int) string {
+			// Your own implementation or use a 3rd-party package
+			// like we do here.
+			//
+			// Note that this is only for english,
+			// but you can accept the language code
+			// and use a map with dictionaries to
+			// pluralize words based on the given language.
+			return pluralize.Pluralize(word, count, true)
+		},
+	}
+	app.I18n.Load("./locales/*/*.yml", "en-US", "el-GR")
+
+	app.Get("/", func(ctx iris.Context) {
+		text := ctx.Tr("HiDogs", iris.Map{
+			"locale": ctx.GetLocale(),
+			"count":  2,
+		}) // prints "Hi 2 dogs".
+		ctx.WriteString(text)
+	})
+
+	return app
+}