- Refactor `installer.clone` into new `repo.Clone` package and method.
- Refactor `sheets.isGitDir` into `repo.GitDir`.
Both of these changes read better, and will facilitate cleaner
architecture when `--update` is implemented.
Modify `Sheets.Load` to not walk hidden directories like `.git`. This
optimization can potentially prevent thousands of system calls from
being made, because `.git` directories can contain many files.
- Re-implemented the project in Golang, and deprecated Python entirely
- Implemented several new, long-requested features
- Refactored cheatsheets into a separate repository