Add shell scripts to install BlocksDS easily

[AntonioND]

Currently, the setup instructions of BlocksDS expect users to copy-paste a bunch of commands. Even though each individual step is explained, this can be intimidating for newcomers.

It would be great if we could have a bash script for Linux and a PowerShell script for Windows to setup everything automatically. The script needs to verify that all required tools are present in the system (for example, if it uses wget to download files, it needs to check if wget is present in the system). It can also ask the user whether to install NFlib and Nitro Engine or not. It could potentially install all ARM builds of libraries that are distributed with wf-pacman. There could also be a script to update packages (something that sets PATH to add wf-pacman to the path and runs wf-pacman -Syu --noconfirm).

The scripts can be developed using the current Dockerfile as reference: https://github.com/blocksds/sdk/blob/074c05f46e45865a2cfd10c2a6de8970c0c54a97/docker/Dockerfile