tester begins to be useful

.gitignore

app/decker.hs

app/tester.hs

resource/deck.html

resource/example/example-meta.yaml

resource/test-question.md

resource/test.tex

resource/tester-example/cross-product-geometry-test.yaml

resource/tester-example/cross-product-math-test.yaml

slides.cabal

src/embed.hs

src/test.hs

src/utilities.hs