Add stream conversion example

Author: Laurynas Butkus

examples/convert_stream.py

@@ -0,0 +1,20 @@
+import convertapi
+import os
+import io
+import tempfile
+
+convertapi.api_secret = os.environ['CONVERT_API_SECRET'] # your api secret
+
+# Example of using content stream to convert to pdf
+# https://www.convertapi.com/txt-to-pdf
+
+content = "Test content string"
+
+upload_io = convertapi.UploadIO(content, 'test.txt')
+
+result = convertapi.convert('pdf', { 'File': upload_io })
+
+saved_files = result.save_files(tempfile.gettempdir())
+
+print("The PDF saved to %s" % saved_files)
+