gpclient: add page (#14060)

Co-authored-by: Managor <42655600+Managor@users.noreply.github.com>
Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/linux/gpclient.md

@@ -0,0 +1,32 @@
+# gpclient
+
+> Connect to a GlobalProtect VPN on Linux via OpenConnect.
+> More information: <https://github.com/yuezk/GlobalProtect-openconnect>.
+
+- Connect to a GlobalProtect VPN using a portal server:
+
+`gpclient connect {{vpn_gateway_url}}`
+
+- Disconnect from the currently connected VPN server:
+
+`gpclient disconnect`
+
+- Launch the graphical user interface (GUI) for VPN management:
+
+`gpclient launch-gui`
+
+- Use OpenSSL workaround to bypass legacy renegotiation errors:
+
+`gpclient connect --fix-openssl {{vpn_gateway_url}}`
+
+- Ignore TLS errors during connection:
+
+`gpclient connect --ignore-tls-errors {{vpn_gateway_url}}`
+
+- Display version:
+
+`gpclient --version`
+
+- Display help for any command:
+
+`gpclient help {{command}}`