Add back compliance kaldi file (#4080)

Author: samanklesaria

docs/source/compliance.kaldi.rst

@@ -0,0 +1,20 @@
+.. py:module:: torchaudio.compliance.kaldi
+
+torchaudio.compliance.kaldi
+===========================
+
+.. currentmodule:: torchaudio.compliance.kaldi
+
+The useful processing operations of kaldi_ can be performed with torchaudio.
+Various functions with identical parameters are given so that torchaudio can
+produce similar outputs.
+
+.. _kaldi: https://github.com/kaldi-asr/kaldi
+
+.. autosummary::
+   :toctree: generated
+   :nosignatures:
+
+   spectrogram
+   fbank
+   mfcc

docs/source/index.rst

@@ -66,6 +66,7 @@ model implementations and application components.
    datasets
    models
    models.decoder
+   compliance.kaldi
    pipelines
 
 .. toctree::