Add failing test cases - Githubissues

@Raza403 can you please add failing test cases here and test that they fail?

Work plan

[x] Copy failing test files to test/fixtures/*.html
[x] Copy test-build-html-validate.mjs to test-that-failures-are-reported.mjs
[x] Add test-that-failures-are-reported.mjs into package.json/scripts/test-build-html-validate step
[x] Update test-that-failures-are-reported.mjs to operate on each fixture, hardcode each one, do not use glob
[x] Update test-that-failures-are-reported.mjs to expect a specific error, hardcode error text, for each test
[x] Update test-that-failures-are-reported.mjs to return exit status 0 (success) if all expected errors are found, otherwise 1

fulldecent / github-pages-template