- Use strcharpart for Unicode character support
- Add warning message if more than one character is entered
- Refactor InsertChar to clarify variable names and flow
- Make user input handling robust against accidental multi-char input
- Add global config for warning message
- Update commands and mappings for flexible argument handling
- Update README.md with instructions and notes for vim-repeat (`.`) support
- Update doc/singlechar.txt: add requirements, usage, and tips for vim-repeat, including installation and dot-repeat behavior
- Move main functions (InsertChar, RepeatSingleChar) to autoload/singlechar.vim, using Vim9script and export for modularity
- Refactor plugin/singlechar.vim to import autoload module and update commands/mappings accordingly
- Prepare for improved maintainability and compatibility with vim-repeat
