Fix file regexp pattern in README

[kevinpapst]

See https://github.com/kimai/kimai/actions/runs/7385039079/job/20089038083

The pull request has only these files changed: https://github.com/kimai/kimai/pull/4514/files

The "blocks.html.twig" file triggers here, because I blindly followed the (wrong pattern?) in the README.

The pattern .*.lock should only match files that end on .lock (like symfony.lock, composer.lock, yarn.lock).

For testing: https://regex101.com/r/mTsQJG/1

Maybe we can further improve on my suggestion, as I am not the biggest regex friend 😁

The README says

In the example above, files with .example extension won't be allowed to be changed.

But the regex also matches 1example.txt.

So maybe the pattern .*\.example$. is even better?

[xalvarez]

You're right, thanks for your contribution!

[kevinpapst]

Thanks for your work here @xalvarez 👍