Migrate "Secure Connections" page and HTTPS+Tor SVG animation to new Lektor site

We need to port "How HTTPS encryption and Tor work in Tor Browser to enhance your privacy and anonymity" content to the new Secure Connections page (old: https://tb-manual.torproject.org/secure-connections/). This page includes an inline SVG animation that requires a dedicated Lektor template. We need to adapt the template implemented in lego: https://gitlab.torproject.org/tpo/web/lego/-/blob/main/templates/secure-connections.html?ref_type=heads