Attempt to document Thread.app_lifetime

gistfile1.txt

=head2 method app_lifetime

    method app_lifetime(Thread:D:) returns Bool:D

Returns C<False> unless the named parameter C<:app_lifetime> is specifically set
to C<True> during object creation. If the method returns C<False> it means that the
the process will only terminate when the thread has finished while C<True> means that
the thread will be killed when the main thread of the process terminates.
    
    my $t1 = Thread.new(code => { for 1..5 -> $v { say $v }});
    my $t2 = Thread.new(code => { for 1..5 -> $v { say $v }}, :app_lifetime);
    
    say $t1.app_lifetime;                 # False
    say $t2.app_lifetime;                 # True