Launch script for half life alyx on proton

launch.sh

#!/bin/bash

# To use this script:
# VCON_PORT=port for vconsole2, or 29000 if not set
# PROTON_DIR=path to proton, fails if not set
# HLA_PATH=path to half life alyx, fails if not set
export  STEAM_COMPAT_DATA_PATH=$HOME/proton
[[ -z "$VCON_PORT" ]] && VCON_PORT=29000
[[ -z "$HLA_PATH" ]] && echo "HLA_PATH is not set" && exit 1
[[ -z "$PROTON_DIR" ]] && echo "PROTON_DIR is not set" && exit 1

# Limit it to 16gb of ram, so we don't crash
ulimit -m 20000000

pushd "$PROTON_DIR" > /dev/null 
echo "Running game"
shift 

./proton run "$HLA_PATH/game/bin/win64/hlvr.exe" -vconport 29000 -console -dev +sv_cheats +map startup -windowed $@ & 
./proton run "$HLA_PATH/game/bin/win64/vconsole2.exe"

popd > /dev/null

why do we need this and what is vconsole2.exe?