Fix CI badge in README and docs

[frantic-rabbit]

Description

Updated the github actions badge in docs

Linked Issue

Fixes #383

Checklist

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't any other open Pull Requests for the required change?
• Does your submission pass pre-commit? ($ pre-commit run --all-files or $ nox -s lint)
• Does your submission pass tests? ($ pytest or $ nox -s tests)
• Does the documentation build with your changes? ($ cd docs; make clean; make html or $ nox -s docs)
• Does your submission pass the doctests? ($ xdoctest ./src/vector or $ nox -s doctests)

Before Merging

• Summarize the commit messages into a brief review of the Pull request.

[Saransh-cpp]

Thanks, @frantic-rabbit! :)