Enable effective usage of docker run with arguments

Reference: https://stackoverflow.com/a/62313159/706031
diff --git a/docker/linux/Dockerfile b/docker/linux/Dockerfile
index 033ac1a..e2d71dc 100644
--- a/docker/linux/Dockerfile
+++ b/docker/linux/Dockerfile
@@ -182,7 +182,7 @@
 # RISCV toolchain
 COPY --from=nuttx-toolchain-riscv /tools/riscv64-unknown-elf-gcc/ riscv64-unknown-elf-gcc/
 ENV PATH="/tools/riscv64-unknown-elf-gcc/bin:$PATH"
- 
+
 # ESP32 toolchain
 COPY --from=nuttx-toolchain-esp32 /tools/xtensa-esp32-elf-gcc/ xtensa-esp32-elf-gcc/
 COPY --from=nuttx-toolchain-esp32 /tools/esp-idf/ esp-idf/
@@ -191,4 +191,4 @@
 COPY --from=nuttx-toolchain-esp32 /tools/blobs/* /tools/blobs/esp32core/
 RUN pip3 install esptool
 
-ENTRYPOINT [ "/bin/bash" ]
+CMD [ "/bin/bash" ]