* use `termion` rather than `ncurses` to limit runtime deps
* cross-compile with `cross` instead of our own dockerfiles/scripts
* update instructions
* update release procedure and GitHub actions to match
* prep changelog for `v0.7.8`
Fixes#160Closes#265
For #210
* update changelog format so that `parse-changelog` is happy.
* add the example from taiki-e/create-gh-release-action verbatim.
Fingers crossed it works in my setup.
