Roadmap for 2.2.0

[GregaVrbancic]

Dear contributors and users,

Yesterday, we released version 2.1.0 which brings new dependency manager, isolated tests and other under the hood improvements. As the release is already uploaded to the pypi, the conda version is still in the making since we have some issues with our conda publishing workflow. However, we will try to fix it as soon as possible.

Of course, all this would not be possible without our amazing contributors. Special mention goes to @firefly-cpp and @zStupan which are responsible for some major and crucial improvements in the codebase.

Since with this release the work does not, I would like to invite everyone to give some feedback and make some propositions and give ideas for future NiaPy releases.

Here are listed some unresolved from previous discussion:

• Refactor algorithms using Individual as proposed in [https://github.com/GWO returns different type of results (individual) than other methods #282#issuecomment-855232867](this comment) by @zStupan .
• Explore potential possibilities and performance gains if we would include Numba in NiaPy project.
• Work on NiaPy-GUI