Readme: fix broken links

[LinasKo]

Description

2 links in Readme were broken. This fixes them.

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)

How has this change been tested, please provide a testcase or example of how you tested the change?

Checked readme page and clicked datsets and annotators links.

Any specific deployment considerations

Docs

• [ ] Docs updated? What were the changes:

[LinasKo]

Thanks!