fix capitalization of PERL/artistic license
fix capitalization of PERL/artistic license

Perl-ites prefer "Perl" for the language and "perl" for the implementation, but never "PERL" (see `perldoc perlfaq1`).

Text referring to a license as a proper noun reads better with the noun capitalized (e.g., "the Artistic License"), and this form is used by `perldoc artistic`.
n7s/choosealicense.com,waldyrious/choosealicense.com,davelab6/choosealicense.com,shalomb/choosealicense.com,JTechMe/choosealicense.com,julianromera/choosealicense.com,derekjones/choosealicense.com,mickaelandrieu/choisirunelicence,drewwyatt/choosealicense.com,cirosantilli/choosealicense.com,JTechMe/choosealicense.com,sieversMartin/choosealicense.com,shalomb/choosealicense.com,github/choosealicense.com,drewwyatt/choosealicense.com,liks79/choosealicense.com,waldyrious/choosealicense.com,matt40k/choosealicense.com,christianbundy/choosealicense.com,github/choosealicense.com,sieversMartin/choosealicense.com,davelab6/choosealicense.com,eogas/choosealicense.com,waldyrious/choosealicense.com,eogas/choosealicense.com,JTechMe/choosealicense.com,derekjones/choosealicense.com,julianromera/choosealicense.com,eogas/choosealicense.com,github/choosealicense.com,drewwyatt/choosealicense.com,n7s/choosealicense.com,christianbundy/choosealicense.com,liks79/choosealicense.com,webfatorial/escolhaumalicenca.com.br,mickaelandrieu/choisirunelicence,mickaelandrieu/choisirunelicence,derekjones/choosealicense.com,n7s/choosealicense.com,shalomb/choosealicense.com,gorcz/choosealicense.com,webfatorial/escolhaumalicenca.com.br,davelab6/choosealicense.com,matt40k/choosealicense.com,gorcz/choosealicense.com,cirosantilli/choosealicense.com,matt40k/choosealicense.com,cirosantilli/choosealicense.com,webfatorial/escolhaumalicenca.com.br,davelab6/choosealicense.com,julianromera/choosealicense.com,christianbundy/choosealicense.com,gorcz/choosealicense.com,sieversMartin/choosealicense.com