Fix the help menu NFS scan and align the FAQ with the installer

- Option 19 scans an NFS server for its exports with pvesm scan nfs
- pveupgrade is described as the interactive package upgrade it starts
- The FAQ describes the wget install command and the Post-Install backups of .bashrc and MOTD
- Two Spanish error titles match the interface

lang/es.json

@@ -1776,6 +1776,7 @@
   "Disabling portmapper/rpcbind for security...": "Deshabilitando portmapper/rpcbind por seguridad...",
   "Discard changes": "Descartar cambios",
   "Discard unapplied changes?": "¿Descartar los cambios sin aplicar?",
+  "Discover NFS exports on a server": "Descubrir los exports NFS de un servidor",
   "Discover targets on portal:": "Detectar destinos en el portal:",
   "Discovering iSCSI targets...": "Descubriendo destinos iSCSI...",
   "Discovery successful": "Detección correcta",
@@ -5993,6 +5994,7 @@
   "Start the VM to begin Windows installation from the mounted ISO.": "Inicie la VM para comenzar la instalación de Windows desde la ISO montada.",
   "Start the applications once they are registered? Answer No if the original containers are still running on another host: both would use the same addresses.": "¿Iniciar las aplicaciones una vez registradas? Responde No si los contenedores originales siguen en marcha en otro host: los dos usarían las mismas direcciones.",
   "Start the converted container:": "Inicie el contenedor convertido:",
+  "Start the interactive Proxmox package upgrade": "Iniciar la actualización interactiva de paquetes de Proxmox",
   "Start the main system upgrade:": "Inicie la actualización principal del sistema:",
   "Start the stack with Proxmox": "Iniciar la pila con Proxmox",
   "Start uploading to PBS — sets a recovery passphrase": "Empezar a subir a PBS — establece una frase de contraseña de recuperación",