<!-- Check all that apply [x] -->

## Check list

- [ ] I have read through the [README](https://github.com/wfxr/minimap.vim/blob/master/README.md) (especially F.A.Q section)
- [ ] I have searched through the existing issues or pull requests
- [ ] I have verified all existing unit tests pass (See the README on how to run)
- [ ] I have added new tests if appropriate
- [ ] I have performed a self-review of my code and commented hard-to-understand areas
- [ ] I have made corresponding changes to the documentation (when necessary)

## Description

<!-- Please include a summary of the change(and the related issue if any). Please also include relevant motivation and context when necessary. -->

## Type of change

- [ ] Bug fix
- [ ] New feature
- [ ] Improvement of existing features
- [ ] Refactor
- [ ] Breaking change
- [ ] Documentation change
- [ ] CI / CD

## Test environment

- OS
    - [ ] Linux
    - [ ] Mac OS X
    - [ ] Windows
    - [ ] Others:
- Vim
    - [ ] Neovim: <Version>
    - [ ] Vim: <Version>
