docs: add documentation for egress via virtualserver

[chase-kiefer]

• update docs that were previously focused on ingress based egress only
• add example virtualserver configuration referenced in the egress tutorial

This PR is to be merged only after Ingress Controller has released the related VirtualServer egress functionality.

Proposed changes

Describe the use case and detail of the change. If this PR addresses an issue on GitHub, make sure to include a link to that issue here in this description (not in the title of the PR).

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• [x] I have read the CONTRIBUTING doc
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have checked that all unit tests pass after adding my changes
• [x] I have updated necessary documentation
• [ ] I have rebased my branch onto main
• [x] I will ensure my PR is targeting the main branch and pulling from my branch from my own fork