Add Speech Commands dataset

[osanseviero]

Adding a Dataset

• Name: Speech commands
• Description: A Dataset for Limited-Vocabulary Speech Recognition
• Paper: https://arxiv.org/abs/1804.03209
• Data: https://www.tensorflow.org/datasets/catalog/speech_commands, Available: http://download.tensorflow.org/data/speech_commands_v0.02.tar.gz
• Motivation: Nice dataset for audio classification training

cc @anton-l

Instructions to add a new dataset can be found here.

[polinaeterna]

self-assign