Open source: remove attachment_partitioner from partition_msg and partition_email (#261)

Author: Paul-Cornell

open-source/core-functionality/partitioning.mdx

@@ -229,17 +229,13 @@ elements = partition_email(text=text, include_headers=True)
 
 `partition_email` includes a `max_partition` parameter that indicates the maximum character length for a document element. This parameter only applies if `"text/plain"` is selected as the `content_source`. The default value is `1500`, which roughly corresponds to the average character length for a paragraph. You can disable `max_partition` by setting it to `None`.
 
-You can optionally partition e-mail attachments by setting `process_attachments=True`. If you set `process_attachments=True`, you’ll also need to pass in a partitioning function to `attachment_partitioner`. The following is an example of what the workflow looks like:
+You can optionally partition e-mail attachments by setting `process_attachments=True`. The following is an example of what the workflow looks like:
 
 ```python
-from unstructured.partition.auto import partition
 from unstructured.partition.email import partition_email
 
 filename = "example-docs/eml/fake-email-attachment.eml"
-elements = partition_email(
-  filename=filename, process_attachments=True, attachment_partitioner=partition
-)
-
+elements = partition_email(filename=filename, process_attachments=True)
 ```
 
 
@@ -377,17 +373,13 @@ elements = partition_msg(filename="example-docs/fake-email.msg")
 
 `partition_msg` includes a `max_partition` parameter that indicates the maximum character length for a document element. This parameter only applies if `"text/plain"` is selected as the `content_source`. The default value is `1500`, which roughly corresponds to the average character length for a paragraph. You can disable `max_partition` by setting it to `None`.
 
-You can optionally partition e-mail attachments by setting `process_attachments=True`. If you set `process_attachments=True`, you’ll also need to pass in a partitioning function to `attachment_partitioner`. The following is an example of what the workflow looks like:
+You can optionally partition e-mail attachments by setting `process_attachments=True`. The following is an example of what the workflow looks like:
 
 ```python
-from unstructured.partition.auto import partition
 from unstructured.partition.msg import partition_msg
 
 filename = "example-docs/fake-email-attachment.msg"
-elements = partition_msg(
-  filename=filename, process_attachments=True, attachment_partitioner=partition
-)
-
+elements = partition_msg(filename=filename, process_attachments=True)
 ```