Added setup guide and launch tools

Start-Arcade.ps1

@@ -0,0 +1,18 @@
+param(
+    [ValidateSet('controller', 'cabinet', 'all')][string]$Mode = 'controller',
+    [string]$Config = "$PSScriptRoot/tools/launch/launcher.ini",
+    [switch]$Check,
+    [switch]$Browser
+)
+$ErrorActionPreference = 'Stop'
+$launchArguments = @("$PSScriptRoot/tools/launch/launch.py", $Mode, '--config', $Config)
+if ($Check) { $launchArguments += '--check' }
+if ($Browser) { $launchArguments += '--browser' }
+if (Get-Command py -ErrorAction SilentlyContinue) {
+    & py -3 @launchArguments
+} elseif (Get-Command python -ErrorAction SilentlyContinue) {
+    & python @launchArguments
+} else {
+    throw 'Python 3 is required. Install it, then reopen PowerShell.'
+}
+exit $LASTEXITCODE