Apache mod_rewrite redirect for non secure requests to secure www. subdomain

In many cases SSL certificates are issued for the "www." domain.
Then you'll want to have all links pointing to "www." domain otherwise you'll see Firefox's error message:

"Secure Connection Failed. The certificate is only valid for www.domain.com"

[code]
RewriteEngine on
#RewriteCond %{SERVER_PORT} ^80$
RewriteCond %{HTTP_HOST} ^domain.com$ [NC]
RewriteCond %{REQUEST_URI} !^/?\.well-known
RewriteRule .* https://www.domain.com%{REQUEST_URI} [QSA,R=301,L]
[/code]

The check for .well-known is done to ensure Let's encrypt is able to access the site via non-ssl if necessary.