Add new guide about speed, add missing config fields

SUMMARY.md

@@ -39,6 +39,7 @@
 * [🐛 Error Handling](guide/error-handling.md)
 * [🔎 Validation](guide/validation.md)
 * [🪝 Hooks](guide/hooks.md)
+* [⚡ Make Fiber Faster](guide/faster-fiber.md)
 
 
 ## Extra

api/fiber.md

@@ -78,6 +78,10 @@ app := fiber.New(fiber.Config{
 | DisablePreParseMultipartForm | `bool` | Will not pre parse Multipart Form data if set to true. This option is useful for servers that desire to treat multipart form data as a binary blob, or choose when to parse the data. | `false` |
 | StreamRequestBody | `bool` | StreamRequestBody enables request body streaming, and calls the handler sooner when given body is larger then the current limit. | `false` |
 | EnablePrintRoutes | `bool` | EnablePrintRoutes enables print all routes with their method, path, name and handler.. | `false` |
+| Network | `string` | Known networks are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only)<br><br>**WARNING:** When prefork is set to true, only "tcp4" and "tcp6" can be chosen. | `NetworkTCP4` |
+| JSONEncoder | `utils.JSONMarshal` | Allowing for flexibility in using another json library for encoding. | `json.Marshal` |
+| JSONDecoder | `utils.JSONUnmarshal` | Allowing for flexibility in using another json library for decoding. | `json.Unmarshal` |
+
 
 ## NewError
 

guide/faster-fiber.md

@@ -0,0 +1,34 @@
+# ⚡ Make Fiber Faster
+
+## Custom JSON Encoder/Decoder
+Since Fiber v2.32.0, we use **encoding/json** as default json library due to stability and producibility. However, the standard library is a bit slow compared to 3rd party libraries. If you're not happy with the performance of **encoding/json**, we recommend you to use these libraries:
+- [goccy/go-json](https://github.com/goccy/go-json1)
+- [bytedance/sonic](https://github.com/bytedance/sonic)
+- [segmentio/encoding](https://github.com/segmentio/encoding)
+- [mailru/easyjson](https://github.com/mailru/easyjson)
+- [minio/simdjson-go](https://github.com/minio/simdjson-go)
+- [wI2L/jettison](https://github.com/wI2L/jettison)
+
+{% code title="Example" %}
+```go
+package main
+
+import "github.com/gofiber/fiber/v2"
+import "github.com/goccy/go-json"
+
+func main() {
+	app := fiber.New(fiber.Config{
+		JSONEncoder: json.Marshal,
+		JSONDecoder: json.Unmarshal,
+	})
+
+	# ...
+}
+```
+{% endcode %}
+
+### References
+- [Set custom JSON encoder for client](../api/client.md#jsonencoder)
+- [Set custom JSON decoder for client](../api/client.md#jsondecoder)
+- [Set custom JSON encoder for application](../api/fiber.md#config)
+- [Set custom JSON decoder for application](../api/fiber.md#config)