[Wiki] Add Basic example about: how to send text to the text field prompt in Developing extensions page

[EnsignMK]

For example it's not obvious how to send "hello world" to the textbox prompt field,
I checked on Developing custom scripts page,there is nothing.

I'm sure every beginner to extensions development would appreciate if this was mentioned anywhere on the Developing extensions wiki page. Considering I needed this feature for my own extension, I decided to figure out how to ,do this. Here it is example I made
https://github.com/EnsignMK/ExampleSendText

it's an example extension to showcase how to send any text you want to the textbox prompt field and for developers to
inspect the code and adjust it to their needs.