docs(engine): clarify Use() registration order

docs/doc.md

@@ -459,6 +459,10 @@ func main() {
 }
 ```
 
+Attach global middleware before registering routes. Routes added before a `Use()` call are not
+retroactively wrapped, while `404` and `405` handlers are rebuilt from the current global
+middleware chain.
+
 ### Custom Middleware
 
 ```go

gin.go

@@ -334,8 +334,9 @@ func (engine *Engine) NoMethod(handlers ...HandlerFunc) {
 	engine.rebuild405Handlers()
 }
 
-// Use attaches a global middleware to the router. i.e. the middleware attached through Use() will be
-// included in the handlers chain for every single request. Even 404, 405, static files...
+// Use attaches a global middleware to the router. Middleware attached through Use() is included
+// in the handlers chain for routes registered after the call. For 404 and 405 requests, Gin
+// rebuilds the handler chain from the current middleware set.
 // For example, this is the right place for a logger or error management middleware.
 func (engine *Engine) Use(middleware ...HandlerFunc) IRoutes {
 	engine.RouterGroup.Use(middleware...)

gin_test.go

@@ -570,6 +570,37 @@ func TestRebuild404Handlers(t *testing.T) {
 	compareFunc(t, router.allNoRoute[1], middleware0)
 }
 
+func TestUseOnlyAppliesToRoutesRegisteredAfterIt(t *testing.T) {
+	signature := ""
+	router := New()
+
+	router.GET("/before", func(c *Context) {
+		signature += "A"
+		c.Status(http.StatusNoContent)
+	})
+
+	router.Use(func(c *Context) {
+		signature += "M"
+		c.Next()
+		signature += "N"
+	})
+
+	router.GET("/after", func(c *Context) {
+		signature += "B"
+		c.Status(http.StatusNoContent)
+	})
+
+	w := PerformRequest(router, http.MethodGet, "/before")
+	assert.Equal(t, http.StatusNoContent, w.Code)
+	assert.Equal(t, "A", signature)
+
+	signature = ""
+
+	w = PerformRequest(router, http.MethodGet, "/after")
+	assert.Equal(t, http.StatusNoContent, w.Code)
+	assert.Equal(t, "MBN", signature)
+}
+
 func TestNoMethodWithGlobalHandlers(t *testing.T) {
 	var middleware0 HandlerFunc = func(c *Context) {}
 	var middleware1 HandlerFunc = func(c *Context) {}