Update README.md in egs2/librimix/tse1 and egs2/wsj0_2mix/tse1

[Emrys365]

This PR adds pre-trained TSE models and the corresponding results to two recipes:

• egs2/wsj0_2mix/tse1 (8kHz)
• egs2/librimix/tse1 (16kHz)

In addition, I also fixed a bug when preparing the transcription in egs2/wsj0_2mix/tse1.

[codecov]

Codecov Report

Merging #5289 (233e903) into master (0971f17) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #5289   +/-   ##
=======================================
  Coverage   76.10%   76.10%           
=======================================
  Files         658      658           
  Lines       59156    59156           
=======================================
  Hits        45022    45022           
  Misses      14134    14134           

Flag	Coverage Δ
test_integration_espnet1	65.96% <ø> (ø)
test_integration_espnet2	47.52% <ø> (ø)
test_python	66.49% <ø> (ø)
test_utils	23.17% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[sw005320]

Thanks a lot!