rename asr egs

examples/aishell/README.md

 # ASR
 
-* s0 for deepspeech2
-* s1 for u2/transformer/conformer
+* asr0 - deepspeech2 Streaming/Non-Streaming
+* asr1 - transformer/conformer Streaming/Non-Streaming
+* asr2 - transformer/conformer Streaming/Non-Streaming with Kaldi feature
+
 
 ## Data
 

examples/librispeech/README.md

 # ASR
 
-* s0 is for deepspeech2 offline
-* s1 is for transformer/conformer/U2
-* s2 is for transformer/conformer/U2 w/ kaldi feat, need install Kaldi
+* asr0 - deepspeech2 Streaming/Non-Streaming
+* asr1 - transformer/conformer Streaming/Non-Streaming
+* asr2 - transformer/conformer Streaming/Non-Streaming with Kaldi feature
+
 
 ## Data
 | Data Subset | Duration in Seconds |

examples/ted_en_zh/README.md

 # TED En -> Zh
 
-* t0 for u2 speech translation
+* st0 - conformer/transformer speech translation