+ As the Perl 6 is renamed to raku, it is good to reflect that https://github.com/Raku/problem-solving/blob/master/solutions/language/Path-to-Raku.md
+ perl6.org is now raku.org
+ change references of perl 6 to raku
+ rename file perl6-pod.html.markdown to raku-pod.html.markdown
+ Perl refers to Perl 5, there is no ambiguity after rename of Perl6 to
Raku, use Perl only to refer to Perl 5
+ fix links inside raku.html.markdown
