Add SlimeVR server

[JovannMC]

This is the link to the project: SlimeVR Server

• I have read the contributing guidelines.
• Use the following format: [Title](link) - Description.
• If the project is closed source add the ![closed source] badge after the (link) but before the -.
• If the project/article is non-free or paywalled add the ![paid] badge after the (link) but before the -.
• Add entries alphabetically to the most appropriate category.
• No unnecessary words like for Tauri, a Tauri plugin and Super-Fast.
• Description does not start with A or An.
• Description is under 24 words.
• Description has no links or parenthesis.
• Use backticks when mentioning package names.
• Double-check spelling and grammar.
• No trailing whitespace is added to the end of any file.
• One suggestion per pull request.
• I understand that my entry will be removed if it violates the guidelines.
• I have signed my commits.

Apps

• The app is original and not too simple.
• The README is in English.
• The app makes a reasonable effort to be fast, lightweight and secure.
• If the app closed source, evidence of it being built with Tauri is included.

Additional Context

The SlimeVR Server is a part of the SlimeVR ecosystem, consisting of open-source hardware and software, to facilitate full-body tracking in VR.