Hi, I'm reading contributing guidelines. I need to create a feature branch in my fork for specific issue and then create a PR on that branch. Do I get it right?

Nah you don’t need to necessarily create a feature branch - once you fork you are kinda free to use your own structure All we ask is that you use good git commit messages and small commits so we can track what’s going on :)

Its really tiny commit, so I did it straight in master in my fork

that works 🙂