* initial implementation of global search
* use tokio::sync::mpsc::unbounded_channel instead of Arc, Mutex, Waker poll_fn
* use tokio_stream::wrappers::UnboundedReceiverStream to collect all search matches
* regex_prompt: unified callback; refactor
* global search doc
* Implement shell interaction commands
* Use slice instead of iterator for shell invocation
* Default to `sh` instead of `$SHELL` for shell commands
* Enforce trailing comma in `commands` macro
* Use `|` register for shell commands
* Move shell config to `editor` and use in command
* Update shell command prompts
* Remove clone of shell config
* Change shell function names to match prompts
* Log stderr contents upon external command error
* Remove `unwrap` calls on potential common errors
`shell` will no longer panic if:
* The user-configured shell cannot be found
* The shell command does not output UTF-8
* Remove redundant `pipe` parameter
* Rename `ShellBehavior::None` to `Ignore`
* Display error when shell command is used and `shell = []`
* Document shell commands in `keymap.md`
* Add preview pane for fuzzy finder
* Fix picker preview lag by caching
* Add picker preview for document symbols
* Cache picker preview per document instead of view
* Use line instead of range for preview doc
* Add picker preview for buffer picker
* Fix render bug and refactor picker
* Refactor picker preview rendering
* Split picker and preview and compose
The current selected item is cloned on every event, which is
undesirable
* Refactor out clones in previewed picker
* Retrieve doc from editor if possible in filepicker
* Disable syntax highlight for picker preview
Files already loaded in memory have syntax highlighting enabled
* Ignore directory symlinks in file picker
* Cleanup unnecessary pubs and derives
* Remove unnecessary highlight from file picker
* Reorganize buffer rendering
* Use normal picker for code actions
* Remove unnecessary generics and trait impls
* Remove prepare_for_render and make render mutable
* Skip picker preview if screen small, less padding
