Pocket TTS: Dockerfile: Install accelerator with make.

Dockerfile

@@ -11,10 +11,11 @@ COPY . .
 
 RUN mkdir build \
     && cd build \
-    && cmake -DCMAKE_BUILD_TYPE=Release ../accelerator \
+    && cmake \
+       -DCMAKE_BUILD_TYPE=Release \
+       -DCMAKE_INSTALL_PREFIX=/app \
+       ../accelerator \
     && make -j$(nproc) \
-    && mkdir -p "$PWD/../bin" \
-    && mv pocket_tts_accelerator "$PWD/../bin/" \
-    && chmod +x "$PWD/../bin/pocket_tts_accelerator" \
+    && make install \
     && cd .. \
-    && rm -rf accelerator
+    && rm -rf accelerator build