Make Bevy dependency repo Main branch & Reserve components for editor layout system

[Atlas16A]

No description provided.

[rewin123]

Since we now have milestones corresponding to the roadmap, I took the liberty of assigning a milestone to this PR. Feel free to change the assigned milestone, as I don't have authority here.

[alice-i-cecile]

@BD103 we want to pin a specific commit for this, not just "main".

[Atlas16A]

CI is still failing but not sure why this time.

[BD103]

Looks like you added bevy as a dependency of the main bevy_editor_prototypes, but not the bevy_panes sub-crate. Could you please move the bevy = { ... } line in Cargo.toml to be under a new [workspace.dependencies] table? (As shown here.) After that, please add bevy.workspace = true under [dependencies] of both Cargo.toml and bevy_panes/Cargo.toml.

By doing this, you add bevy as a dependency available to bevy_panes specifically. I chose to make bevy a workspace dependency so that you don't have to copy the commit hash everywhere, and so that upgrades are easier.

[BD103]

Ok, we're almost there! (Don't worry!)

The (hopefully final) CI error is the missing documentation lint. For all items in bevy_panes (the add() function and the components), could you add a short doc description? Doc comments start in ///, and there are plenty examples around to base things on. Comments can be a single sentence, though feel free to go into further detail!