Added myself to manifesto

I run a private XMPP server (=no public registration, but connected to XMPP network).

I think "regular" server operators should also have a way to show their commitment to a more secure network. Ubiquitous S2S encryption won't work if not all servers support it. Therefore it is important that not only the public service providers adhere to these guidelines/goals, but also people that just run XMPP servers for themselves & friends.

If you want to differentiate between public service providers and "private/unimportant service providers", why not create two different sections for the signatures? :)

Thanks for creating this manifesto, it's an important step towards more secure communication online!