[docs] Update/fix documentation where needed

[ottaviohartman]

Describe the bug
After setting up my local dev environment, I've noticed some errors in the documentation. I'll go through and fix them in a PR; this issue is to track these errors.

[github-actions]

Hello there omh1280! 👋

Thank you and congratulations 🎉 for opening your very first issue in this project! 💖

In case you want to claim this issue, please comment down below! We will try to get back to you as soon as we can. 👀

[ottaviohartman]

Claim

[Haarolean]

@omh1280 Hey,

sure, would be nice to get it updated.

Thanks

[schnells]

I also saw some documentation linking errors, this one for example:

kafka-ui/README.md

Line 72 in ce8627e

- [Docker-compose files](documentation/guides/yaml-description.md)

Are you gonna fix those too? If not I could also contribute via PR

[ottaviohartman]

Yeah I'll fix that one and others in that PR ^. Just link or comment where else needs fixing