share/mk/doc.translate.mk: Improve `make po`

[dbaio]

Summary

share/mk/doc.translate.mk: Improve `make po`

- Create .pot (Portable Object Template) files for the en_US documents
  Do not ignore en_US language and generate a `.pot` file instead of a `.po`.
  These are used as template for tools like Zanata.

- Execute `msgattrib` even on a new `[.po|.pot]` file
  This will be useful to wrap long message lines and avoid bigger diffs in
  the future.

Approved by: ???
Differential Revision: https://reviews.freebsd.org/D16726

[wosch]

The diff looks good. Did you checked that the current output is the same after your change?

[dbaio]

In D16726#357416, @wosch wrote:

The diff looks good. Did you checked that the current output is the same after your change?

Thank you for the feedback.

Yes, it's the same content with wrapped lines and this is the same behavior when you execute make po with an existing lang.po file.

Here you can see a .po file with wrapped lines.

Here is the output after a make tran followed by a build.

Is this file maintained by doceng?