[docs] silk to pcm and wav

[iftaken]

There is a bug in pysilk converting silk to wav, it is recommended to use pilk, first convert silk to pcm, and then use ffmepg to convert to wav format

[codecov[bot]]

Codecov Report

Merging #340 (d96f31d) into master (e96706c) will not change coverage. The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #340   +/-   ##
=======================================
  Coverage   41.50%   41.50%           
=======================================
  Files          27       27           
  Lines        1930     1930           
=======================================
  Hits          801      801           
  Misses       1129     1129           

Flag	Coverage Δ
unittests	41.50% <ø> (ø)

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[wj-Mcat]

Thanks for your contribution and improvement, can you add some description about what you have done in this pr, so that other developers can get it quickly.

[wj-Mcat]

The final process, you should sign the cla license so that I can merge the pr.

[wj-Mcat]

Wechaty Contributors Nomination

Link to https://github.com/wechaty/PMC/issues/16

[wj-Mcat]

@iftaken please fix the conflicts.

[wj-Mcat]

ping @iftaken