Harden shell scripts

[fpistm]

• Unified shell script name across host and add missing extension
• Make shell scripts ShellCheck compliant
• Use shfmt to format shell scripts
• Add the formatting options file

[fpistm]

@kbumsik I've made some change i the run_arduino_gen.sh to be compliant with ShellCheck. I've tested and it works anyway if you can review it and give your feedback, this will be really appreciate. Thanks in advance.

[kbumsik]

@fpistm LGTM, I tested it on my hardware and it works well too. It is interesting that echo -n is not POSIX compliant though.

[fpistm]

Thanks @kbumsik

It is interesting that echo -n is not POSIX compliant though.

Yes it is.