Move using-northstar/direct-connect.md to the dedicated using-northstar directory

[hxdeci]

Also fixes overlooked issue with this page linking to commands.md

[GeckoEidechse]

Don't forget to also update here

NorthstarWiki/docs/modding-and-development/development/northstarmasterserver/README.md

Line 11 in 351a7f5

There's no need to host your own master server to play games with other people, you can use [direct connect](../../../installing-northstar/using-northstar/direct-connect.md) or just setup a [normal server](../../../hosting-a-server-with-northstar/basic-listen-server.md) that announces itself to `northstar.tf`. This tutorial is aimed for those who want to contribute improvements to the code or test their own changes to the project.

[GeckoEidechse]

Requested changes have been addressed. Looks good now ^^