fix typo in README

[neuhaus]

What kind of change does this PR introduce? (check at least one)

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] Feature (non-breaking change which adds functionality)
• [ ] Code style update
• [ ] Refactor (refactoring or adding test which isn't a fix or add a feature)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Build-related changes
• [x] Other, please describe:

Does this PR introduce a breaking change? (check one)

• [ ] Yes
• [x] No

Did you test your solution?

• [ ] I lightly tested it in one browser
• [ ] I deeply tested it in several browsers
• [ ] I wrote tests around it (unit tests, integration tests, E2E tests)

Problem Description

Solution Description

Side Effects, Risks, Impact

• [x] N/A

Aditional comments:

just a single character typo in the documentation.