### Description
Given all the shell files that now exist in the repo, would be nice to
have linting/formatting around them (in addition to the existing
shellcheck which doesn't do anything to format the shell code). This PR
introduces `shfmt` to both check for changes and apply formatting when
the associated make targets are called.
* docker works
* more epub tests
* changelog version
* support epub + odt + rtf
* update dockerfile
* revert..
* install pandoc on ci env
* pandoc docker grab bashed on arch
* move arch into image
* move back to base image