Add Gitbook documentation to target info

[MatthijsKamstra]

Hi
I have been working on documentation for different target for some time now:

• haxe and JavaScript
• haxe and PHP
• haxe and nodejs

In the HaxeManual most of the targets are not that well documented (take PHP for example), @markknol also made some issues related to this (#139, #138, #137, #136, #135 opened on 12 Apr 2015)

Because documentation writing is difficult, I thought it would be a good idea to add these gitbooks to the official documentation.

For example: https://haxe.org/manual/target-php.html.
Add a chapter "community driven documentation" with some disclaimers like "bla bla bla, community, bla, not maintained by Haxe developers team but friendly developers, bla ... link"

I can transfer the repos if needed

Let me know what you think!

Grt Matthijs

[Simn]

We can link these from the appropriate pages, sure. I don't think we should go beyond that because the overall style of your documentation is very different from the rest of the manual.

[MatthijsKamstra]

cool, I will update my documentation again

and will write something that can be evaluated if the tone of voice is similar to the manual