Add --global to fix sync doc pipline (#21916)

Author: NoriZC

tools/SyncDocsToMicrosoftDocsOrg.ps1

@@ -29,8 +29,8 @@ foreach ($SyncPath in $Config.SyncPath)
 
 $SyncFile = Split-Path $SyncPath -Leaf
 
-git config user.email "[email protected]"
-git config user.name "azure-powershell-bot"
+git config --global user.email "[email protected]"
+git config --global user.name "azure-powershell-bot"
 
 cd $WorkSpace
 git clone $RepoCloneLink