v0.35.1: performance, AGPL licensing and documentation overhaul

- Web Server reads static files inline; proxy middleware chain flattened
- About window with license summary and project links; AGPL-3.0-or-later
- Rewritten documentation: feature list, screenshots, performance guide
- Fix false spikes in per-Vhost request-rate charts

src/server/listeners.rs

@@ -64,7 +64,9 @@ fn h2c_attempt<B>(request: &Request<B>) -> bool {
         .filter_map(|value| value.to_str().ok())
         .flat_map(|value| value.split(','))
         .any(|value| value.trim().eq_ignore_ascii_case("h2c"))
-        || request.headers().contains_key("http2-settings")
+        || request
+            .headers()
+            .contains_key(::http::HeaderName::from_static("http2-settings"))
 }
 
 fn hpack_integer(out: &mut Vec<u8>, value: usize, prefix_bits: u8, first: u8) {