Description:
The `Check For Updates` menu item is not available, because the `Help` menu is not shown, unless I open a document (existing or new).

I should not be forced to open a document to check for updates.

A lot of macOS apps have this in the application menu.

Some other applications (e.g. FireFox, Thunderbird) have the check for update as a separate button in the `About` dialog.  I don't necessarily suggest this, but it's an option (event though it's a two step process).

There may be other operations that also could benefit from being visible without requiring a document to be open.


Steps to Reproduce:
1. Open LibreOffice (without any documents open).
2. No way to check if there are any updates.

Actual Results:  
No `Check For Updates` menu item is available.

Expected Results:
I would expect to be able to search for updates at any time, whether or not any documents are open.


Reproducible: Always

User Profile Reset: No

Additional Info:


User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:54.0) Gecko/20100101 Firefox/54.0