docs: revise Python SDK docs

Author: davidturnbull

src/lingodotdev/__init__.py

@@ -1,8 +1,9 @@
 """
-Lingo.dev Python SDK
+Public entry point for the Lingo.dev Python SDK.
 
-A powerful localization engine that supports various content types including
-plain text, objects, chat sequences, and HTML documents.
+The package exposes :class:`~lingodotdev.engine.LingoDotDevEngine`, the
+asynchronous client used to access the Lingo.dev localization API. Refer to the
+engine module for detailed usage guidance.
 """
 
 __version__ = "1.3.0"