Corrects documentation to include sub-tracking in the API

docs/api.rst

@@ -1,8 +1,14 @@
 API
 ===
 
-.. automodule:: gpu_tracker
-
+gpu_tracker.tracker
+-------------------
 .. automodule:: gpu_tracker.tracker
     :members:
     :undoc-members:
+
+gpu_tracker.sub_tracker
+-----------------------
+.. automodule:: gpu_tracker.sub_tracker
+    :members:
+    :undoc-members:

src/gpu_tracker/sub_tracker.py

@@ -1,4 +1,4 @@
-"""The ``sub_tracker`` module contains the ``SubTracker`` class which can alternatively be imported directly from the ``gpu_tracker`` package."""
+"""The ``sub_tracker`` module contains the ``SubTracker`` class which can alternatively be imported directly from the ``gpu_tracker`` package. Additionally, it contains the ``SubTrackingAnalyzer`` class which generates the ``SubTrackingResults`` from the data produced by the ``SubTracker`` and finally the ``TrackingComparison`` which generates the ``ComparisonResults`` comparing the ``SubTrackingResults`` of multiple tracking sessions."""
 from __future__ import annotations
 import inspect
 import os