Add docker and gitpod support

[b4oshany]

[dashezup]

Thanks for your contribution, I've never heard of gitpod before and personally I'm not interested in trying and test it. But this pull request would make sense for people who need to run it on gitpod.

I'll leave this PR opening. You can keep the branch of your fork linked to this PR updated in case you are keep using it. But it's unlikely to be merged.

btw plain text files are supported to have new line character at the end of the file, it's probably that case that your text editor or IDE does not automatically add new line character at the end of the file, most of those files in this PR does not include new line character at the end of the file currently. you should enter a new line at the end of the file. (this behavior is different than on Vim, which automatically add new line character at the end of the file by default).