[io grant] Improve docs for IO::Path.slurp

Author: zoffixznet

doc/Type/IO/Path.pod6

@@ -472,7 +472,9 @@ entity.
 
     multi method slurp(IO::Path:D: :$bin, :$enc)
 
-Return the file content for this path, like L<slurp|/routine/slurp>.
+Read all of the file's content and return it as either L<Buf>, if C<:$bin>
+is C<True>, or if not, as L<Str> decoded with C<:$enc> encoding, which defaults
+to C<utf8>. See L«C<&open>|/routine/open» for valid values for C<:$enc>.
 
 =head2 method spurt