It shouldn't be necessary in our setup, and it just makes keys
needlessly longer.

Seems like it might be needed by wp2pgpmail.

And disallow all requests that are not static content.

According to the docs in
https://httpd.apache.org/docs/current/rewrite/flags.html#flag_l using
[L] in an .htaccess context incurs the risk of infinite recursion,
which is exactly what we were seeing in production for non-existing
.php files. Use [END] instead.

Update the WP Multisite section according to
https://wordpress.org/support/article/htaccess/#wordpress-3-5-and-up

Add the 'intl', 'imagick' and 'zip' modules, which are not required
but recommended, and may actually be useful.

Fixes issue ai/noblogs-wp#89.

These should help with converting widgets from legacy to
new 'blocks'.

Merges the contents of ai3/docker/noblogs (composer branch).