update docs

docs/manual.en.md

@@ -82,6 +82,7 @@
       - [reconstruct\_dissect](#reconstruct_dissect)
       - [reconstruct\_hdr](#reconstruct_hdr)
       - [csum\_fix](#csum_fix)
+    - [conntrack](#conntrack)
     - [Obtaining IP addresses](#obtaining-ip-addresses)
     - [Receiving and sending Packets](#receiving-and-sending-packets)
       - [rawsend](#rawsend)
@@ -2084,6 +2085,25 @@ Functions for fixing checksums. Since strings in Lua are immutable, these functi
 
 Direct reconstruction of individual headers is rarely necessary. Typically, all tasks are handled by functions working with dissects.
 
+### conntrack
+
+```
+function conntrack_feed(dissect, reconstruct_opts)
+```
+
+"Feed" dissect to conntrack the way as if it was received from the network.
+aaa
+2 values are returned : [track](#the-track-table-structure) and bool value "outgoing".
+outgoing is true if a new conntrack record was created and it was a SYN packet in case of tcp or any packet in case of udp.
+If conntrack record already exists outgoing is true if the record was found by direct tuple - src_ip, src_port, dst_ip, dst_port.
+If the record was found by reverse tuple - dst_ip, dst_port, src_ip, src_port - outgoing is false.
+
+The function can come in handy if you are obfuscating and transmitting data in a distorted form. For example, tcp is converted to icmp or the SYN flag is corrupted.
+The receiving end will issue the first corrupted packet without track, because it is either not tcp and not udp, or there was no valid tcp handshake.
+After deobfuscation, you can correct the situation by executing conntrack_feed and assigning desync.track its result.
+
+If conntrack is disabled or the packet is not valid tcp or udp, nil is returned.
+
 ### Obtaining IP addresses
 
 ```