* squashed WIP commits
* hide_gitignore working with config
* pass reference to new config parameter of file_picker()
* update config option name to match name on walk builder
* add comments to config and documentation of option to book
* add git_ignore option to WalkBuilder within prompt in commands.rs
* WIP: add FilePickerConfig struct
* WIP: cleanup
* WIP: add more options including max_depth
* WIP: changed defaults to match ignore crate defaults
* WIP: change WalkBuilder in global_search() to use config options
* WIP: removed follow_links, changed max_depth to follow config setting
* WIP: update book with file-picker inline table notation
* update documentation for file-picker config in book
* adjusted to [editor.file-picker] in book configuration.md
* adjust comments in editor.rs to be doc comments, cleanup
* adjust comments
* adjust book
* Implement `hx --tutor` and `:tutor` to load `tutor.txt`
* Document `hx --tutor` and `:tutor`
* Change `Document::set_path` to take an `Option`
* `Document::set_path` accepts an `Option<&Path>` instead of `&Path`.
* Remove `Editor::open_tutor` and make tutor-open functionality use
`Editor::open` and `Document::set_path`.
* Use `PathBuf::join`
Co-authored-by: Ivan Tham <pickfire@riseup.net>
* Add comments explaining unsetting tutor path
Co-authored-by: Ivan Tham <pickfire@riseup.net>
* improve idle completion trigger
* add completion-trigger-len to book
* rename semantics_completion to language_server_completion and optimize idle completion trigger