If you ask why there was .hg and .hgignore in a Git repository, it's because I completely forgot this project is my first ever project using Mercurial as SCM. As such, I foolishly `git init` the repository and have to update both .gitignore and .hgignore to finish the changes. You can also see the Mercurial version of this thing at here:https://hg.sr.ht/~tsukii/robin