Pod::Formatting code not completely handled in =begin/=end item blocks

[tbrowder]

The first line after the '=begin item' is properly formatted, but formatting code in following paras within the block is ignored.

Given:

=begin item
 C<foo>
    
B<foo> is...
=end item

that rakudoc is rendered as:

* `foo`

B<foo> is...

UPDATE

But if there is no leading space, it works properly:

Given:

=begin item
C<foo>
    
B<foo> is...
=end item

that rakudoc is rendered as:

* `foo`

`foo` is...

[coke]

See skaji/mi6#184 for a related bug on formatting code processing.