Releasing v1.0.0.

Added tests for `append()` and `extend()` with `newline` set to `Fals…

…e` to achieve 100% coverage.

Releasing v3.0.0.

Updated the link to the GitHub Actions shield as per badges/shields#8671

Added newline to EOF

Fixed tests to run on GitHub Actions

Removed unnecessary links to `load()`, `stream()`, `save()` and `appe…

…nd()` in the README file

Added 'ndjson' as a keyword in the project metadata

Created a changelog

Adding a link to Codecov