chore: add nim_test.yml

[vil02]

This PR adds a very simple CI for this repo (and fixes some bugs in the existing *.nim files).

Note that there are still some warnings in the existing files.

The future work is definitely to setup this project using nimble, but this also would require things like project structure change, which is way too far beyond the scope of this PR.

Regarding the shellscripts: #21

[ZoomRmc]

Looks good, besides the proposed change and this:
I propose replacing the Bash scripts in this PR with a nimscript task from #21.

[dlesnoff]

Do we want to require passing tests on devel?

Sorry I meant checking against devel too.
I would like to know if some code works under devel but does not work with the stable version.

[dlesnoff]

I do not want to setup a Nimble/Atlas project file. I have had many problems switching between developer and user versions of the repositories. I am confused by the recent changes brought to Nimble that made it quite unstable. ) The imposed Nimble directory structure will probably conflict with the directory structure of the Algorithms repository.

Nimble is not really necessary. What advantages does it really bring ?

• Tasks in Nimble can be written in a classical .nims file.
• Dependencies handling ? We do not want dependencies.

[dlesnoff]

Improves greatly the repository's state and workflow. I need @Panquesito7 's approval to merge this.

[Panquesito7]

Awesome. Thanks! 🚀

[ZoomRmc]

Nice work everybody!