Add github actions

[hardliner66]

It should be quite easy to add some github actions to run the tests on each commit/PR and deploy the files to github pages, if the build was successful. This would guarantee that contributions don't break tests and that people can simply test the VM directly in the browser without having to manually compile it.

[dalnefre]

I believe that some of the recent improvement to the automated test infrastructure by @jamesdiacono should make this easier. I'd love to see an automatically-updated github-hosted uFork VM debugger instance.

[hardliner66]

I was recently trying to get github pages to work, but they don't set the wasm mime type properly, so I need to work around that somehow. I'll check how trunk or wasm-pack loads the wasm, because I know they work on pages.

I can testing for that too, so that only fully tested code gets pushed to pages.