This is necessary to workaround ownership issues across function calls.
The issue notably arised when implementing the registers into `Editor`
and I was getting annoyed again when implementing copy/pasting into
system clipboard.
The problem is addressed by using macro calls instead of function calls.
There is no notable side effect.
* Add convenience/clarity wrapper for Range initialization
* Add keycode parse and display methods
* Add remapping functions and tests
* Implement key remapping
* Add remapping book entry
* Use raw string literal for toml
* Add command constants
* Make command functions private
* Map directly to commands
* Match key parsing/displaying to Kakoune
* Formatting pass
* Update documentation
* Formatting
* Fix example in the book
* Refactor into single config file
* Formatting
* Refactor configuration and add keymap newtype wrappers
* Address first batch of PR comments
* Replace FromStr with custom deserialize
