How do I configure mediawiki to show heading numbering/lettering in the document?

When the table of contents is generated, it numbers sections based upon their heading:

1. section 1  
2. section 2  
2.1 section 2.1  
2.2 section 2.2  
3. section 3

I would like these section numbers to appear at the paragraph level as well:

1. (section 1 header text)
... section 1 content ...

2. (section 2 header text)
... section 2 content ....

Any tips?

There is a user-preference to make all headings use outline numbering, but no way to make that a default for all users. Here's a few lines of code which can be added to your LocalSettings.php file which do that.

$wgExtensionFunctions[] = 'wfNumberHeadings';
function wfNumberHeadings() {
    global $wgUser;
    $wgUser->setOption('numberheadings', true);
}

According to this page, you can also change in LocalSettings.php to make this behavior the default.

$wgDefaultUserOptions['numberheadings'] = 1;