Add test case for metadata query and github actions to run tests

This PR sets up github actions to build and test this project. It also adds a test for the failing test case mentioned in my issue #4 It seems that the github actions won't run in your repo until this goes to master, but you can see the runs here: https://github.com/anisjonischkeit/dynomark/pull/1 https://github.com/anisjonischkeit/dynomark/actions/runs/14547924263/job/40815699107 ``` Run go test -v ./... === RUN TestMetadataQuery main_test.go:1[4](https://github.com/anisjonischkeit/dynomark/actions/runs/14547924263/job/40815699107#step:5:5): LIST FROM "examples/" WHERE [author] IS Shakespeare is expected to output: - shakespeare_quotes.md Got - movie_reviews.md - shakespeare_quotes.md - tasks.md - test.md --- FAIL: TestMetadataQuery (0.00s) ```