Add hotwords support to .Net (#689)

dotnet-examples/offline-decode-files/run-hotwords.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [ ! -d ./sherpa-onnx-zipformer-en-2023-04-01 ]; then
+  wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  tar xvf sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+  rm sherpa-onnx-zipformer-en-2023-04-01.tar.bz2
+fi
+
+if [ ! -f ./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt ]; then
+cat >./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt <<EOF
+▁ QUA R TER S
+▁FOR E VER
+EOF
+fi
+
+dotnet run \
+  --tokens=./sherpa-onnx-zipformer-en-2023-04-01/tokens.txt \
+  --encoder=./sherpa-onnx-zipformer-en-2023-04-01/encoder-epoch-99-avg-1.onnx \
+  --decoder=./sherpa-onnx-zipformer-en-2023-04-01/decoder-epoch-99-avg-1.onnx \
+  --joiner=./sherpa-onnx-zipformer-en-2023-04-01/joiner-epoch-99-avg-1.onnx \
+  --num-threads=2 \
+  --decoding-method=modified_beam_search \
+  --files ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/0.wav \
+  ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/1.wav
+
+dotnet run \
+  --hotwords-file=./sherpa-onnx-zipformer-en-2023-04-01/hotwords_en.txt \
+  --hotwords-score=2.0 \
+  --tokens=./sherpa-onnx-zipformer-en-2023-04-01/tokens.txt \
+  --encoder=./sherpa-onnx-zipformer-en-2023-04-01/encoder-epoch-99-avg-1.onnx \
+  --decoder=./sherpa-onnx-zipformer-en-2023-04-01/decoder-epoch-99-avg-1.onnx \
+  --joiner=./sherpa-onnx-zipformer-en-2023-04-01/joiner-epoch-99-avg-1.onnx \
+  --num-threads=2 \
+  --decoding-method=modified_beam_search \
+  --files ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/0.wav \
+  ./sherpa-onnx-zipformer-en-2023-04-01/test_wavs/1.wav
+
+# 0.wav: QUARTER -> QUARTERS
+# 1.wav: FOR EVER -> FOREVER