[Documentation] Remove nomad branding

[Kardzhilov]

Pre-flight checklist

• I have searched existing issues and this bug has not been reported yet
• I am running the latest available version of TREK

TREK version

2.9.11

Describe the bug

Hey i noticed a couple of things that have not been changed in the branding change from Nomad to Trek

• The readme of the project features screenshots featuring the deprecated "Nomad" branding.

• The demo url https://demo-nomad.pakulat.org should probably be updated.

• Searching though the codebase for nomad returns a lot of results, most of which i expect should be changed https://github.com/search?q=repo%3Amauriceboe%2FTREK%20nomad&type=code

Steps to reproduce

• Go to readme page of the project.
• Look at demo url
• Search codebase for the string "nomad"

Expected behavior

No mention of nomad on the landing page for the project

Deployment method

Docker Compose

Host OS

No response

Accessing TREK from

Desktop browser

Browser (if applicable)

No response

Relevant logs or error output

Screenshots

No response

Additional context

No response