Update Readme to include how to initialize Azure Document Intelligence correctly?

[hf-fdsilva]

Could someone provide an updated readme or how to, on how to initialize the markitdown package to use Azure Document Intelligence via api key, esp with python?

the only thing I'm seeing on the readme is pointing to an endpoint, but there doesn't seem to be any documentation on what it expects for the API key if you aren't using Azure AD to auth to Doc Intel service.

The only semblence of information I found from browsing through the issues tab is this (from #1168):

Initialize MarkItDown

md = MarkItDown(docintel_endpoint = AZURE_DOC_INT_ENDPOINT,
docintel_file_types = ['pdf'],
docintel_credential = AzureKeyCredential(AZURE_DOC_INT_KEY))

Thanks!