add VT30 in README. fix working directory issue of scripts

Scripts/compile_codec.sh

@@ -3,3 +3,4 @@ mkdir out
 cd out
 cmake ..
 make
+cd ../..

Scripts/compile_tr.sh

@@ -14,3 +14,4 @@ do
 		../../NlpCodec/out/NlpCodec encode $txt_file $nlp_file
 	fi
 done
+cd ../..

Scripts/create_new_tr.sh

@@ -10,6 +10,7 @@ fi
 
 cd NlpTr
 cp VT25.template.json "VT25."$1".json"
+cp VT30.template.json "VT30."$1".json"
 cp VT35.template.json "VT35."$1".json"
 cp VT40.template.json "VT40."$1".json"
 cp VT50.template.json "VT50."$1".json"