mv_docker.sh : Better shebang and Added set -e flag

mv_docker.sh

@@ -1,6 +1,8 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-WSL_DIR=/d/WSL2
+set -e
+
+WSL_DIR='/d/WSL2'
 
 WSLS="$(wsl --list | sed 1d | cut -d' ' -f 1 | sed $'s/[^[:print:]\t]//g' | head -n -1)"