This PR renames the `h_stack` and `v_stack` to `h_flex` and `v_flex`,
respectively.
We were previously using `h_stack` and `v_stack` to match SwiftUI, but
`h_flex` and `v_flex` fit better with the web/flexbox terminology that
the rest of GPUI uses.
Additionally, we were already calling the utility functions used to
implement `h_stack` and `v_stack` by the new names.
Release Notes:
- N/A
This makes it a bit more approachable to implement.
This required converting the state of Component to AnyElement, which
costs an allocation. I'm hoping this will be ok performance-wise now
that AnyElements use bump allocation, but I need to benchmark still.
This PR extracts the `Story` component into a separate `story` crate so
that it can be shared among various crates that define stories.
Release Notes:
- N/A
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Co-authored-by: Nate Butler <iamnbutler@gmail.com>
