Fix sidebark wiki link
# Mimiker Wiki
- [Home](https://github.com/cahirwpz/mimiker/wiki)
-- [Structure](https://github.com/cahirwpz/mimiker/wiki/structure.md)
+- [Structure](https://github.com/cahirwpz/mimiker/wiki/structure)
- [Commenting](https://github.com/cahirwpz/mimiker/wiki/commenting)
- [Onboarding](https://github.com/cahirwpz/mimiker/wiki/onboarding)
- [Test infrastructure](https://github.com/cahirwpz/mimiker/wiki/tests)
