remove trailing whitespaces and add support matrix (#102)

Signed-off-by: Marvin Drees <marvin.drees@9elements.com>

README.md

@@ -51,7 +51,7 @@ See Developing section below for more information.
 lneto is currently being used primarily by embedded developers and those who need a lighter alternative to gVisor in terms of memory usage and binary size.
 
 - [**soypat/cyw43439**](https://github.com/soypat/cyw43439): Enabling internet access on [Raspberry Pi Pico W](https://www.raspberrypi.com/products/raspberry-pi-pico/). See [`examples`](https://github.com/soypat/cyw43439/tree/main/examples).
-- [**tinygo-org/espradio**](https://github.com/tinygo-org/espradio): Enabling internet access on [Espressif's ESP32s](https://www.espressif.com/en/products/socs/esp32)
+- [**tinygo-org/espradio**](https://github.com/tinygo-org/espradio): Enabling internet access on [Espressif's ESP32s](https://www.espressif.com/en/products/socs/esp32).
 - [**TamaGo**](https://github.com/usbarmory/tamago): Enabling networking on Go baremetal projects. See [go-net project](https://github.com/usbarmory/go-net).
 - [**netbird.io**](https://netbird.io/)(planned): Secure remote P2P access.
 - [**soypat/lan8720**](https://github.com/soypat/lan8720): Enabling internet access with 100M ethernet PHY devices. 
@@ -79,13 +79,43 @@ PASS
 ok      github.com/soypat/lneto/x/xnet  2.926s
 ```
 
+## Protocol Support Matrix
+
+> **Generated 2026-04-27.** This table may not always reflect the current state of the codebase.
+> Allocation figures are derived from benchmark tests run on amd64.
+> `—` denotes no standalone benchmark exists for that protocol; those packages follow the same zero-allocation design principle documented in the codebase.
+
+| Protocol | RFC / Spec | Status | Package | Allocs/op | Notes |
+|----------|-----------|:------:|---------|:---------:|-------|
+| Ethernet II | IEEE 802.3 | ✅ | `ethernet` | 0 ¹ | Frame parsing, CRC-32 |
+| ARP | RFC 826 | ✅ | `arp` | 0 ¹ | Request/reply, hardware address cache |
+| IPv4 | RFC 791 | ✅ | `ipv4` | 0 ² | Frame parsing, ones-complement checksum |
+| ICMPv4 | RFC 792 | ✅ | `ipv4/icmpv4` | — | Echo (ping) client handler |
+| UDP | RFC 768 | ✅ | `udp` | — | Handler + thread-safe `Conn` |
+| TCP | RFC 9293 | ✅ | `tcp` | 0 ²³ | Full state machine, SYN cookies, retransmit queue, `Conn`/`Listener` |
+| DNS | RFC 1035 | ✅ | `dns` | — | Client (A/AAAA query) |
+| DHCPv4 | RFC 2131 | ✅ | `dhcpv4` | — | Client + Server |
+| NTP | RFC 5905 | ✅ | `ntp` | — | Client |
+| mDNS | RFC 6762 | ✅ | `mdns` | — | Client (service announcement + query) |
+| HTTP/1.1 headers | RFC 9110, RFC 9112 | ✅ | `http/httpraw` | 2 ⁴ | Header parse/format; no field normalization |
+| Ethernet PHY/MDIO | IEEE 802.3 cl.22/45 | ✅ | `phy` | — | Bare-metal PHY management via MDIO |
+| IPv6 | RFC 8200 | 🟡 | `ipv6` | — | Frame parsing only; no stack handler |
+| ICMPv6 | RFC 4443 | ❌ | — | — | Not implemented |
+| DHCPv6 | RFC 8415 | ❌ | — | — | Not implemented |
+| TLS 1.3 | RFC 8446 | ❌ | — | — | Not implemented |
+
+¹ `BenchmarkARPExchange` — full ARP request/response exchange over Ethernet: **0 B/op, 0 allocs/op**
+² `BenchmarkTCPHandshake` — TCP 3-way handshake over Ethernet/IPv4: **0 B/op, 0 allocs/op**
+³ `BenchmarkSYNCookie_Generate` / `BenchmarkSYNCookie_Validate` — SYN cookie generation and validation: **0 B/op, 0 allocs/op each**
+⁴ `BenchmarkParseBytes` — HTTP/1.1 request header + body parsing: **240 B/op, 2 allocs/op**
+
 ## Packages
 - `lneto`: Low-level Networking Operations, or "El Neto", the networking package. Zero copy network frame marshalling and unmarshalling.
     - [`lneto/validation.go`](./validation.go): Packet validation utilities
 - [`lneto/internet`](./internet): Userspace IP/TCP networking stack. This is where the magic happens. Integrates many of the listed packages.
     - [`lneto/internet/pcap`](./internal/pcap): Packet capture and field breakdown utilities. Wireshark in the making.
 - [`lneto/http/httpraw`](./http/httpraw/): Heapless HTTP header processing and validation. Does no implement header normalization.
-- [`lneto/tcp`](./ntp): TCP implementation and low level logic.
+- [`lneto/tcp`](./tcp): TCP implementation and low level logic.
 - [`lneto/dhcpv4`](./dhcpv4): DHCP version 4 protocol implementation and low level logic.
 - [`lneto/dns`](./dns): DNS protocol implementation and low level logic.
 - [`lneto/ntp`](./ntp): NTP implementation and low level logic. Includes NTP time primitives manipulation and conversion to Go native types.