feat(docker): add healthcheck and wget dependency

Adds a healthcheck endpoint and updates Dockerfile/README
to include wget and define healthcheck logic.

lib/routing/routes.go

@@ -3,6 +3,7 @@ package routing
 import "github.com/gin-gonic/gin"
 
 type Handlers struct {
+	Health             gin.HandlerFunc
 	Index              gin.HandlerFunc
 	ShowBox            gin.HandlerFunc
 	BoxLogin           gin.HandlerFunc
@@ -34,6 +35,7 @@ type Handlers struct {
 }
 
 func Register(router *gin.Engine, handlers Handlers) {
+	router.GET("/health", handlers.Health)
 	router.GET("/", handlers.Index)
 
 	router.GET("/box/:id", handlers.ShowBox)