This commit introduces feature flags to make it possible for widget
library authors to depend on a specific version of crossterm without
causing version conflicts. This should make it easier for libraries and
apps to update crossterm versions more easily.
The available feature flags are `crossterm_0_28` and `crossterm_0_29`.
By default, the latest version is enabled. If a multiple features are
enabled we choose the latest version. We will in general support at
least the last two major (0.x) versions of crossterm, and will only
remove versions in a major version bump.
Adds summary-level crate organization documentation to all crates
explaining the modular workspace structure and when to use each crate.
Links to ARCHITECTURE.md for detailed information.
Backend code is now moved to `ratatui-crossterm`, `ratatui-termion` and
`ratatui-termwiz`. This should be backwards compatible with existing code.
Co-authored-by: Josh McKinney <joshka@users.noreply.github.com>
