Remove WikiHelp page from TDF Wiki - Confusing contributors

Hello Olivier and other contributors :slight_smile:

I know we aren't usually doing this, but since the help on the wiki is
being deprecated, would you mind removing the following wiki page?

  * https://wiki.documentfoundation.org/Development/Wikihelp

It is very well indexed on search engines, which means this is confusing
users when they want to contribute to the help.

Instead of removing, we can do redirection[1] to this [2] instead.

Thanks in advance for your help,

Regards,

[1] https://www.mediawiki.org/wiki/Help:Redirects

[2] https://wiki.documentfoundation.org/Documentation