Update networking layer w/ CURL and emscripten impl

External/curl-8.17.0/docs/cmdline-opts/http2-prior-knowledge.md

@@ -0,0 +1,29 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Long: http2-prior-knowledge
+Tags: Versions
+Protocols: HTTP
+Added: 7.49.0
+Mutexed: http1.1 http1.0 http2 http3
+Requires: HTTP/2
+Help: Use HTTP/2 without HTTP/1.1 Upgrade
+Category: http
+Multi: boolean
+See-also:
+  - http2
+  - http3
+Example:
+  - --http2-prior-knowledge $URL
+---
+
+# `--http2-prior-knowledge`
+
+Issue a non-TLS HTTP request using HTTP/2 directly without HTTP/1.1 Upgrade.
+It requires prior knowledge that the server supports HTTP/2 straight away.
+HTTPS requests still do HTTP/2 the standard way with negotiated protocol
+versions in the TLS handshake.
+
+Since 8.10.0 if this option is set for an HTTPS request then the application
+layer protocol version (ALPN) offered to the server is only HTTP/2. Prior to
+that both HTTP/1.1 and HTTP/2 were offered.