Replace Outdated Unicode Advice with Modern UTF-8 Best Practices

[davorg]

Update Unicode sections to reflect Perl 5.40+ standards. Replace old module references like Unicode::Map8 with modern idioms using use utf8, proper IO layers (open, binmode) and Encode. Include examples of working with UTF-8 files and strings.

[briandfoy]

Take a look at the Unicode Primer section of Learning Perl. I think the key here is that people have to understand that there are several data boundaries involved, and it's not as simple as doing everything right inside Perl.

• editor settings to read and save the source correctly
• terminal settings to display output as the right locale
• for browsers, sending the right chartype
• for servers, setting the right default chartype
• and so on.