[py-tx] restored comment

python-threatexchange/threatexchange/cli/storage/interfaces.py

@@ -1,4 +1,28 @@
 # Copyright (c) Meta Platforms, Inc. and affiliates.
+
+"""
+Common interface for persisting pytx configuration and concepts.
+Most of the individual components of pytx are find to use piecemeal, and
+the full interface covers the most complex and complete useage. A usecase
+with one collection of hashes using one algorithm might be better off 
+hardcoding those things rather than fully implementing the interface.
+# Migration Notes
+There's an earlier attempt at these interfaces used for CLI at
+<@Mackay-Fisher add the right pointer to the CLI storage>.
+During the development of Hasher-Matcher-Actioner 2.0 
+(github.com/facebook/ThreatExchange/tree/main/hasher-matcher-actioner/)
+we realized that the original attempt at this wouldn't meet the needs
+of that code and wrote a new interface. 
+As of 12/2024, we are now migrating that interface from HMA into pytx
+proper as part of a migration to dbm 
+(github.com/facebook/ThreatExchange/issues/1687). The general approach is:
+1. Copy the interface unchanged from HMA to pytx
+2. Release a new version of pytx
+3. Delete the copy in HMA and update all references to the pytx version
+In parallel, we intend to slowly migrate the CLI storage components to
+follow the same interface.
+"""
+
 import abc
 from dataclasses import dataclass
 import typing as t