add GH action to check/publish animint book

[tdhock]

these days before merging a PR, I am re-building https://github.com/tdhock/animint-book to make sure nothing breaks.
this suggests we should add a GH action which does this automatically for every push.
For publishing it would be nice to have at least the master branch.

[Faye-yufan]

Hi @tdhock , do you think checking for compilation errors in the GH action is enough? I recall when I worked on the color_off function, most issues from the manual seemed to be related to visual effects, which required a visual inspection. Do you feel there's a need to create tests specifically for these visual effects?

[tdhock]

you are right it probably will require a manual visual inspection, but it would be useful to have that automatically built and deployed via actions (rather than on my own laptop). hopefully things like color_off should be covered in tests?