[rosalind] add initial docs for itwv example
[rosalind] add initial docs for itwv example

stmuk/perl6-examples,perl6/perl6-examples,stmuk/perl6-examples,Quinny/perl6-examples,stmuk/perl6-examples,perl6/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,stmuk/perl6-examples,stmuk/perl6-examples,shlomif/perl6-examples,Quinny/perl6-examples,Quinny/perl6-examples,perl6/perl6-examples,Quinny/perl6-examples,shlomif/perl6-examples,shlomif/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,Quinny/perl6-examples