Update UoT protocol

docs/configuration/shared/udp-over-tcp.md

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+# UDP over TCP
+
+!!! warning ""
+
+    It's a proprietary protocol created by SagerNet, not part of shadowsocks.
+
+The UDP over TCP protocol is used to transmit UDP packets in TCP.
+
+### Structure
+
+```json
+{
+  "enabled": true,
+  "version": 2
+}
+```
+
+!!! info ""
+
+    The structure can be replaced with a boolean value when the version is not specified.
+
+### Fields
+
+#### enabled
+
+Enable the UDP over TCP protocol.
+
+#### version
+
+The protocol version, `1` or `2`.
+
+2 is used by default.
+
+### Application support
+
+| Project      | UoT v1               | UoT v2     |
+|--------------|----------------------|------------|
+| sing-box     | v0 (2022/08/11)      | v1.2-beta9 |
+| Xray-core    | v1.5.7 (2022/06/05)  | /          |
+| Clash.Meta   | v1.12.0 (2022/07/02) | /          |
+| Shadowrocket | v2.2.12 (2022/08/13) | /          |
+
+### Protocol details
+
+#### Protocol version 1
+
+The client requests the magic address to the upper layer proxy protocol to indicate the request: `sp.udp-over-tcp.arpa`
+
+#### Stream format
+
+| ATYP | address  | port  | length | data     |
+|------|----------|-------|--------|----------|
+| u8   | variable | u16be | u16be  | variable |
+
+*ATYP / address / port*: Uses the SOCKS address format.
+
+#### Protocol version 2
+
+Protocol version 2 uses a new magic address: `sp.v2.udp-over-tcp.arpa`
+
+##### Request format
+
+| isConnect | ATYP | address  | port  |
+|-----------|------|----------|-------|
+| u8        | u8   | variable | u16be |
+
+**version**: Fixed to 2.
+
+**isConnect**: Set to 1 to indicates that the stream uses the connect format, 0 to disable.
+
+**ATYP / address / port**: Request destination, uses the SOCKS address format.
+
+##### Connect stream format
+
+| length | data     |
+|--------|----------|
+| u16be  | variable |
+
+##### Non-connect stream format
+
+As the same as the stream format in protocol version 1.