Fix sphinx gallery list in io doc (#2736)

Summary:
Specifying multiple object in `:minigallery:` directive shows duplicated tutorials.

This commit fixes it by listing tutorials based on module used.

https://output.circle-artifacts.com/output/job/c3da2a22-40d5-4e2d-b73a-28b39e712817/artifacts/0/docs/io.html

Before:
<img width="694" alt="Screen Shot 2022-10-07 at 7 04 35 AM" src="https://user-images.githubusercontent.com/855818/194427092-ca1202e7-0731-4c18-b48b-24923d692a4a.png">

After:

<img width="648" alt="Screen Shot 2022-10-07 at 7 03 14 AM" src="https://user-images.githubusercontent.com/855818/194426950-5b780458-2bf0-43ef-b020-fcbbfdf8d41b.png">

Pull Request resolved: https://github.com/pytorch/audio/pull/2736

Reviewed By: carolineechen

Differential Revision: D40160247

Pulled By: carolineechen

fbshipit-source-id: 547496f9b569ff7a4d70db97e90f3ea503344477

docs/source/io.rst

@@ -13,6 +13,6 @@ torchaudio.io
    StreamReader
    StreamWriter
 
-.. rubric:: Tutorials using Streaming API
+.. rubric:: Tutorials using ``torchaudio.io``
 
-.. minigallery:: torchaudio.io.StreamReader torchaudio.io.StreamWriter
+.. minigallery:: torchaudio.io

examples/tutorials/device_asr.py

@@ -328,3 +328,8 @@ if __name__ == "__main__":
 #
 #    hello world
 #
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`
+#

examples/tutorials/online_asr_tutorial.py

@@ -248,3 +248,7 @@ run_inference()
 #
 
 run_inference()
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`

examples/tutorials/streamreader_advanced_tutorial.py

@@ -487,3 +487,7 @@ _display(3)
 # ^^^^^^^^^^^^^^^^^^
 
 _display(4)
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`

examples/tutorials/streamreader_basic_tutorial.py

@@ -612,3 +612,7 @@ for i, vid in enumerate(vids2):
             ax.set_ylabel("Stream 2")
 plt.tight_layout()
 plt.show(block=False)
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`

examples/tutorials/streamwriter_advanced.py

@@ -324,3 +324,7 @@ with s.open():
 #
 # [`code <https://download.pytorch.org/torchaudio/tutorial-assets/udp.py>`_]
 #
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`

examples/tutorials/streamwriter_basic_tutorial.py

@@ -672,3 +672,8 @@ Video(get_path("example.mp4"), embed=True)
 # Carefully watching the video, it can be
 # observed that the sound of "s" (curio\ **si**\ ty, be\ **si**\ des, thi\ **s**\ ) has
 # more energy allocated on higher frequency side (right side of the video).
+
+######################################################################
+#
+# Tag: :obj:`torchaudio.io`
+#