[doc] perlop: add additional simpler example of using "<<" with "()"

[jidanni]

On perlop there is a rather complex example of using << with ():

   myfunc(<< "THIS", 23, <<'THAT');
Here's a line
or two.
THIS
and here's another.
THAT

There perhaps ought to be a an additional simpler example first,

print uc(<<EOF);
abc
EOF

Except I don't know where on that page to put it.

Perhaps someone could put something like that somewhere on that page. Thanks.

[rwp0]

I always do:

my $person = 'John';

print uc <<~ "TEXT"; # add space around, quote the token, might always use ~
  Hello, $person!  
  And the text goes on.
  TEXT

Which results in:

HELLO, JOHN!  
AND THE TEXT GOES ON.

Not sure if bareword token is recommended.

Wish ~ were always there, added by default (for indentation = readability).

---

NB. EOF (end of file) in the example could be replaced ith EOT (end of text) for clarity

And that "THIS" could include a $variable within the heredoc (to use its surrounding double quotes for a purpose)

[jidanni]

Well all that is great to mention too.
All I know is a user is trying to lookup how to stuff a <<EOF into ( ) in a hurry.