new language: Perl

[aldy505]

Add Perl language support for the detection.

You can learn Perl first here:

• https://learnxinyminutes.com/docs/perl/
• https://www.tutorialspoint.com/perl/index.htm

Some test cases:

• https://rosettacode.org/wiki/Hello_world/Standard_error#Perl
• https://rosettacode.org/wiki/FizzBuzz#Perl
• https://rosettacode.org/wiki/Palindrome_detection#Perl
• https://rosettacode.org/wiki/Happy_numbers#Perl
• https://rosettacode.org/wiki/Most_frequent_k_chars_distance#Perl
• https://rosettacode.org/wiki/Merge_and_aggregate_datasets#Perl
• https://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort#Perl
• https://rosettacode.org/wiki/Sorting_algorithms/Heapsort#Perl
• https://rosettacode.org/wiki/Sorting_algorithms/Merge_sort#Perl
• https://rosettacode.org/wiki/Sorting_algorithms/Quicksort#Perl
• https://rosettacode.org/wiki/Ludic_numbers#Perl
• https://rosettacode.org/wiki/Floyd-Warshall_algorithm#Perl