Improve contributing documentation clarity

[Karanrajpurohit855]

Fixes #1754

Improved contributing documentation by adding clearer steps and beginner-friendly instructions.

[aloctavodia]

Thanks for your contribution. This may be potentially useful, but it needs much more work.

[aloctavodia]

We don't have this label. I think the label is "documentation", please double-check. Also, "good first issue" could be useful (also double check the name).

[aloctavodia]

I see that we have that label, my bad!

[OriolAbril]

Moreover, I strongly disagree with this statement. Things labeled "User Documentation" are not necessarily easier than the rest. If a tag is mentioned it should be the "Beginner" one but we don't have much capacity to dedicate to issue triaging, so I would instead focus on advise that is not label dependent. It is key to understand what the issue is talking about, if it is still relevant, if it can be reproduced... Even for issues labelled "Beginner" when we have them they might be for someone who is a beginner on open source but already an intermediate ArviZ user, or for someone who is new to ArviZ but somewhat familiar with open source.

[aloctavodia]

This is only for people that wants to contribute code. You don't need to do this to report issues. So it should be in a different place, maybe a subsection of "contributing code". Additionally, if someone is a beginner, does this list help or do we need something more explicit? And if not a beginner, not very useful, which makes the "For Beginners" heading weird.

[OriolAbril]

I think this whole "how to contribute" section should be removed. This is only a bullet point version of the content already present in the first link within the "Contributing code" section of this same page.

[OriolAbril]

The PR description says this is supposed to close #1754 but at least for now this is very clearly not the case. The issue is very clear that the updates should be done to the contributing guide on the website, not to this CONTRIBUTING.md and has a much larger scope

[OriolAbril]

It might be useful to add some content specific to how beginners can find things to work on within the contributing guide. That being said, I am strongly against adding this directly to this markdown file. We already have a much more extensive contributing guide on the website so I think we should keep this page extremely short and with links to that page. A potential location for this kind of content could be https://python.arviz.org/en/stable/contributing/contributing_prs.html