bad url for dejavu-fonts in v2.22 doc

[David Zelinsky]

On this page: 

http://lilypond.org/doc/v2.22/Documentation/contributor/requirements-for-running-lilypond

there is a link for DejaVu fonts that points to <www.dejavu-fonts.org>.
However, dejavu-fonts.org is apparently owned by an internet hosting
company, which seems to have nothing to do with the DejaVu font family.
In particular the linked page--though it calls itself DejaVu-fonts with
a fancy logo--has no information about the fonts, or any links to the
correct site.

According to Wikipedia, the official web site of the actual DejaVu fonts
is <dejavu-fonts.github.io>.

-- 
David Zelinsky