Readme style

[bmaher]

One-line summary.

Improves #13.

Description

Centres heading and badges in the README.

Types of Changes

What types of changes does your code introduce? Keep the ones that apply:

• Documentation / non-code

Review

Reviewers' checklist:

• If this PR implements new flows or changes existing ones, are there good tests for these flows? If this PR rather removes flows, are the obsolete tests removed as well?
• Is the documentation still up-to-date and exhaustive? This covers both technical (in source files) and functional (under docs/) documentation.
• Is the changelog updated?
• Does the new version number correspond to the actual changes from this PR? In doubt, refer to https://semver.org.

After this PR

Any follow-up action necessary?

[zincr[bot]]

🤖 zincr found 0 problems , 0 warnings

✅ Large Commits
✅ Specification
✅ Dependency Licensing