no issue
- the email previews API should return html and plaintext content that contains any email cards and where any valid replacement strings have been replaced with desired fallbacks
- unknown/invalid replacement strings should appear as entered by the user (no %% wrappers that are used internally)
- move all test files from core/test to test/
- updated all imports and other references
- all code inside of core/ is then application code
- tests are correctly at the root level
- consistent with other repos/projects
Co-authored-by: Kevin Ansfield <kevin@lookingsideways.co.uk>