vpn: split the vpn article into openvpn and wireguard

wiki/openvpn.md

@@ -0,0 +1,29 @@
+# OpenVPN
+
+[OpenVPN](https://openvpn.net) is a free software to create a VPN via an
+encrypted TLS connection.
+
+## Set up
+
+In the following sections the different set ups of OpenVPN usages are described.
+
+### Server
+
+The software can be set up via [Docker](/wiki/docker.md) with the
+[kylemanna image](./docker/kylemanna_-_openvpn.md).
+Additionally to this a client is needed on the system that need access to the
+server software.
+
+### Client
+
+OpenVPN clients can be found for many devices.
+For Android for example there is
+[OpenVPN for Android in the F-Droid store](https://f-droid.org/de/packages/de.blinkt.openvpn/).
+For most linux distributions there is a package called `openvpn`.
+
+### Proxy
+
+For OpenVPN a proxy acts as an intermediary between the system communicating
+with the proxy and the OpenVPN server.
+A proxy can be set up via [Docker](/wiki/docker.md) with the
+[jonohill image](./docker/jonohill_-_docker-openvpn-proxy.md).