Add simple app

Signed-off-by: Jan Tytgat <jan.tytgat@corelayer.eu>

go.mod

@@ -0,0 +1,3 @@
+module git.flexabyte.io/flexabyte/go-kit
+
+go 1.24.1

pkg/app/app.go

@@ -0,0 +1,13 @@
+package app
+
+import "fmt"
+
+func New() *App {
+	return &App{}
+}
+
+type App struct{}
+
+func (a *App) Execute() {
+	fmt.Println("Hello World")
+}