Added a wrapper script for writer to generate sdk (#24267)

* Added a wrapper script for writer to generate sdk

* output sdk repo root path

* Set default value for typespec project folder.

Author: raych1

eng/scripts/TypeSpec-Generate-Sdk.ps1

@@ -0,0 +1,35 @@
+[CmdletBinding()]
+param (
+  [Parameter(Position = 0)]
+  [ValidateNotNullOrEmpty()]
+  [string] $SdkRepoRootDirectory,
+  [Parameter(Position = 1)]
+  [string] $TypeSpecProjectDirectory = ".", # A directory of `tspconfig.yaml` or a remoteUrl of `tspconfig.yaml`
+  [Parameter(Position = 2)]
+  [string] $CommitHash,
+  [Parameter(Position = 3)]
+  [string] $RepoUrl
+)
+
+if ($TypeSpecProjectDirectory -contains ".") {
+  $TypeSpecProjectDirectory = Resolve-Path $TypeSpecProjectDirectory
+}
+
+try {
+  Push-Location $SdkRepoRootDirectory
+  $commonScript = Join-Path . "eng/common/scripts/TypeSpec-Project-Process.ps1"
+  if (Test-Path $commonScript) {
+    . $commonScript -TypeSpecProjectDirectory $TypeSpecProjectDirectory -CommitHash $CommitHash -RepoUrl $RepoUrl
+    if ($LASTEXITCODE) {
+      exit $LASTEXITCODE
+    }
+  }
+  else {
+    Write-Error "Cannot find $commonScript at $SdkRepoRootDirectory"
+  }
+}
+finally {
+  Pop-Location
+}
+
+exit 0