Docs: new documentation site (#2723)

This commit adds a VitePress build to the main repository,
aiming to ditch GitHub Wiki. Moving further, we're going to
host our own documentation site eithor on GitHub Pages or
something alike.

docs/premium/experimental-features.md

@@ -0,0 +1,19 @@
+---
+sidebarTitle: Experimental Features
+sidebarOrder: 9
+---
+
+# Experimental Features
+
+Occasionally we make new features that would require a fair amount of testing before having it in the main release. These features are marked as experimental and are disabled by default.
+
+::: warning
+Some features listed here can be unstable, and might get removed in any future version - we do not recommend using them unless you have a specific reason to do so.
+:::
+
+## Sniff TLS SNI
+
+```yaml
+experimental:
+  sniff-tls-sni: true
+```