Added characters to Dockerfile

Dockerfile

@@ -21,6 +21,7 @@ FROM golang:1.23-alpine
 EXPOSE 8080
 VOLUME /sorted
 VOLUME /frontend
+VOLUME /characters
 
 ENV PORT 8080
 ENV DB_HOST ""
@@ -29,6 +30,7 @@ ENV DB_USERNAME ""
 ENV DB_PASSWORD ""
 ENV DB_NAME ""
 ENV MUSIC_PATH ""
+ENV CHARACTERS_PATH ""
 
 COPY --from=build_go /app/main .
 COPY ./songs/ ./songs/