@nutomic Idk if this stands for the 'documentation', more like a guide. I don't know, I didn't need a guide, but I'm a power user, just experimenting in the wild. For the end users, I guess there should be as little documentation as possible. Idk, it might be more challenging to do, but a javascripty interactive tour over the Lemmy would do its job.

This is a great initiative. Based on the areas listed in the post, it seems like the focus is primarily targeted towards end users instead of administrators or moderators. If that's the intent, making the docs more "accessible" (ie more links to the docs, more mentions of the docs on places like join-lemmy.org) may be helpful, especially if the docs are mentioned as more than just technical documentation (eg FAQs, More Info, Learn More, etc.).

One thing that is still a little unclear to me is how communities with the same name are handled. For example, if there is a community called popular_community created on three different Lemmy instances, will a Lemmy user subscribing to one instance's popular_community automatically subscribe the Lemmy user to the other two instances' popular_community (assuming the instances are federated with each other, the user hasn't blocked the other instances, etc.)? What if a Mastodon user (or another non-Lemmy Fediverse user) does that instead of a Lemmy user? If someone tags/mentions/etc. one of instance's popular_community, will the tag/mention/etc. appear on the community within the other instances? What if a Lemmy user subscribes to more than one popular_community and gets banned from one? Is there a way to prevent multiple communities with the same name across Lemmy instances or to make one instance's community systemically recognized as the "official" community (short of reaching out to each community's moderators/administrators to manually link to the single "official" community)? What happens if one instance's administrator shuts down or removes it's instance's popular_community ? How do any of these answers change depending on which Lemmy instance the Lemmy user registers on (if any change at all)?

Basically divide it in two main sections: for USERS and for DEVELOPERS. The first one like a guide/manual: about how this platform works for the average user (less tech stuff), graphical content, clients, etc. And the second one like a documentation/resources module: about how the platform works in-depth (API, Frontend/Backend dev, etc.).

For this I would like to know if there are any things that [are] still unclear now.

I'm registered on Lemmygrad. Lemmygrad and Lemmy are federated, I see this post. How come I can't see all Lemmy.ml communities? Is that Lemmygrad's decision? Is that something I could override with a different Lemmy client, but without having to register in the Lemmy.ml instance?
As reference, the community librewolf is not accessible from Lemmygrad.ml.

mobile apps

The API and protocol would be the most important for me. Admin documentation (how to run things) would be second on my wishlist.