Support for RISC-V architecture (riscv64 Docker image)

[jplegat]

As more distributions are starting to officially support and increase adoption of riscv64 - in addition to Docker support - it would be great to have support for a riscv64 Docker image for those running RISC-V dev boards.

Thanks a lot for this project!

[jplegat]

If anyone’s interested, I’ve built a Linux/RISCV-64 image and pushed it to https://hub.docker.com/repository/docker/jplegat/glances/tags - now it's happily running on a Milk-V Mars board. Feel free to take a look and let me know if you have any questions! - I've just updated the line FROM alpine:${IMAGE_VERSION} as base to FROM riscv64/alpine:${IMAGE_VERSION} as base in the alpine.Dockerfile and ran make docker.