docs: Fix paths to badges

[joconnor-ecaa]

Description

Old links were pointing to specific versions of a Github Gist, which means they never updated.

Current coverage is 74%

Checklist

• [x] Dependencies install correctly in a clean environment and code executes;
• [x] Test coverage extended; created tests fail without the change (if possible);
• [x] All tests passing;
• [x] Commits follow a type convention (e.g. https://gist.github.com/brianclements/841ea7bffdb01346392c#type);
• [x] Extended the README, documentation and/or docstrings, if necessary;