Update prepdocs.ps1

need to switch for pwsh windows forward slash './data/*'  otherwise no data is processed

PS /Users/alexzeltov/git/azure-search-openai-demo> python ./scripts/prepdocs.py '.\data\*' --searchkey "XZnvXI20iBoBfucFfsObjMTvVYXny0txh6n81NvwnGAzSeBUiHAL" --storageaccount $env:AZURE_STORAGE_ACCOUNT --container $env:AZURE_STORAGE_CONTAINER --searchservice $env:AZURE_SEARCH_SERVICE --index $env:AZURE_SEARCH_INDEX -v
Ensuring search index gptkbindex exists
Search index gptkbindex already exists
Processing files...
PS /Users/alexzeltov/git/azure-search-openai-demo> python ./scripts/prepdocs.py './data/*' --searchkey "XZnvXI20iBoBfucFfsObjMTvVYXny0txh6n81NvwnGAzSeBUiHAL" --storageaccount $env:AZURE_STORAGE_ACCOUNT --container $env:AZURE_STORAGE_CONTAINER --searchservice $env:AZURE_SEARCH_SERVICE --index $env:AZURE_SEARCH_INDEX -v 
Ensuring search index gptkbindex exists
Search index gptkbindex already exists
Processing files...
Processing './data/Northwind_Standard_Benefits_Details.pdf'
        Uploading blob for page 0 -> Northwind_Standard_Benefits_Details-0.pdf
        Uploading blob for page 1 -> Northwind_Standard_Benefits_Details-1.pdf

scripts/prepdocs.ps1

@@ -9,4 +9,4 @@ foreach ($line in $output) {
 Write-Host "Environment variables set."
 
 pip install -r ./scripts/requirements.txt
-python ./scripts/prepdocs.py '.\data\*' --storageaccount $env:AZURE_STORAGE_ACCOUNT --container $env:AZURE_STORAGE_CONTAINER --searchservice $env:AZURE_SEARCH_SERVICE --index $env:AZURE_SEARCH_INDEX -v
+python ./scripts/prepdocs.py './data/*' --storageaccount $env:AZURE_STORAGE_ACCOUNT --container $env:AZURE_STORAGE_CONTAINER --searchservice $env:AZURE_SEARCH_SERVICE --index $env:AZURE_SEARCH_INDEX -v