v1.5.1 to add demo sending in chunks

#### Releases v1.5.1

1. Add examples [Async_AdvancedWebServer_SendChunked](https://github.com/khoih-prog/AsyncWebServer_Ethernet/tree/main/examples/Async_AdvancedWebServer_SendChunked) and [AsyncWebServer_SendChunked](https://github.com/khoih-prog/AsyncWebServer_Ethernet/tree/main/examples/AsyncWebServer_SendChunked) to demo how to use `beginChunkedResponse()` to send large `html` in chunks
2. Use `allman astyle` and add `utils`

Author: khoih-prog

CONTRIBUTING.md

@@ -30,25 +30,47 @@ Arduino IDE version: 1.8.19
 ESP8266_NODEMCU_ESP12E using ESP8266_W5500 Ethernet
 ESP8266 core v3.0.2
 OS: Ubuntu 20.04 LTS
-Linux xy-Inspiron-3593 5.15.0-48-generic #54~20.04.1-Ubuntu SMP Thu Sep 1 16:17:26 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
+Linux xy-Inspiron-3593 5.15.0-52-generic #58~20.04.1-Ubuntu SMP Thu Oct 13 13:09:46 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
 
 Context:
 I encountered a crash while using this library
-
 Steps to reproduce:
 1. ...
 2. ...
 3. ...
 4. ...
 ```
 
+### Additional context
+
+Add any other context about the problem here.
+
+---
+
 ### Sending Feature Requests
 
 Feel free to post feature requests. It's helpful if you can explain exactly why the feature would be useful.
 
 There are usually some outstanding feature requests in the [existing issues list](https://github.com/khoih-prog/AsyncWebServer_Ethernet/issues?q=is%3Aopen+is%3Aissue+label%3Aenhancement), feel free to add comments to them.
 
+---
+
 ### Sending Pull Requests
 
 Pull Requests with changes and fixes are also welcome!
 
+Please use the `astyle` to reformat the updated library code as follows (demo for Ubuntu Linux)
+
+1. Change directory to the library GitHub
+
+```
+xy@xy-Inspiron-3593:~$ cd Arduino/xy/AsyncWebServer_Ethernet_GitHub/
+xy@xy-Inspiron-3593:~/Arduino/xy/AsyncWebServer_Ethernet_GitHub$
+```
+
+2. Issue astyle command
+
+```
+xy@xy-Inspiron-3593:~/Arduino/xy/AsyncWebServer_Ethernet_GitHub$ bash utils/restyle.sh
+```
+