Adding upstream version 2.52.6.

Signed-off-by: Daniel Baumann <daniel@debian.org>

docs/guide/grouping.md

@@ -0,0 +1,79 @@
+---
+id: grouping
+title: 🎭 Grouping
+sidebar_position: 2
+---
+
+:::info
+In general, the Group functionality in Fiber behaves similarly to ExpressJS. Groups are declared virtually and all routes declared within the group are flattened into a single list with a prefix, which is then checked by the framework in the order it was declared. This means that the behavior of Group in Fiber is identical to that of ExpressJS.
+:::
+
+## Paths
+
+Like **Routing**, groups can also have paths that belong to a cluster.
+
+```go
+func main() {
+  app := fiber.New()
+
+  api := app.Group("/api", middleware) // /api
+
+  v1 := api.Group("/v1", middleware)   // /api/v1
+  v1.Get("/list", handler)             // /api/v1/list
+  v1.Get("/user", handler)             // /api/v1/user
+
+  v2 := api.Group("/v2", middleware)   // /api/v2
+  v2.Get("/list", handler)             // /api/v2/list
+  v2.Get("/user", handler)             // /api/v2/user
+
+  log.Fatal(app.Listen(":3000"))
+}
+```
+
+A **Group** of paths can have an optional handler.
+
+```go
+func main() {
+  app := fiber.New()
+
+  api := app.Group("/api")      // /api
+
+  v1 := api.Group("/v1")        // /api/v1
+  v1.Get("/list", handler)      // /api/v1/list
+  v1.Get("/user", handler)      // /api/v1/user
+
+  v2 := api.Group("/v2")        // /api/v2
+  v2.Get("/list", handler)      // /api/v2/list
+  v2.Get("/user", handler)      // /api/v2/user
+
+  log.Fatal(app.Listen(":3000"))
+}
+```
+
+:::caution
+Running **/api**, **/v1** or **/v2** will result in **404** error, make sure you have the errors set.
+:::
+
+## Group Handlers
+
+Group handlers can also be used as a routing path but they must have **Next** added to them so that the flow can continue.
+
+```go
+func main() {
+    app := fiber.New()
+
+    handler := func(c *fiber.Ctx) error {
+        return c.SendStatus(fiber.StatusOK)
+    }
+    api := app.Group("/api") // /api
+
+    v1 := api.Group("/v1", func(c *fiber.Ctx) error { // middleware for /api/v1
+        c.Set("Version", "v1")
+        return c.Next()
+    })
+    v1.Get("/list", handler) // /api/v1/list
+    v1.Get("/user", handler) // /api/v1/user
+
+    log.Fatal(app.Listen(":3000"))
+}
+```