Wiki cleanup

I don't know if it's still true for en_US help, but by the past, the
*files* contained links to the how-to and to the Calc functions.

By files, do you mean the in program help files?

Olivier

should have more info about it, but maybe there is a need to check if
links are still pointing to the good page?

I found at least one bad link on the help wiki
https://help.libreoffice.org/Calc/Statistical_Functions_Part_Two.

Some wiki pages were under "How Tos" and others under "HowTo". I merged
everything under "HowTo", but this one links to a page under "How Tos", so
now it gets redirected.

--Kenneth