feat(vh): update Valheim start parameters

lgsm/config-default/config-lgsm/vhserver/_default.cfg

@@ -16,9 +16,17 @@ port="2456"
 gameworld="${selfname}"
 public="1"
 savedir="$HOME/.config/unity3d/IronGate/Valheim"
+logFile=""
+saveinterval="1800"
+backups="4"
+backupshort="7200"
+backuplong="43200"
+# If crossplay is empty, it's off. Fill with any text to make true
+# Crossplay is currently not working on Linux dedicated servers, so for now the default is false (emtpy)
+crossplay=""
 
 ## Server Parameters | https://docs.linuxgsm.com/configuration/start-parameters#additional-parameters
-startparameters="-name '${servername}' -password ${serverpassword} -port ${port} -world ${gameworld} -public ${public} -savedir '${savedir}'"
+startparameters="-name '${servername}' -password ${serverpassword} -port ${port} -world ${gameworld} -public ${public} -savedir '${savedir}' -logFile '${logFile}' -saveinterval ${saveinterval} -backups ${backups} -backupshort ${backupshort} -backuplong ${backuplong} ${crossplay:+-crossplay}"
 
 #### LinuxGSM Settings ####