Document IRC:UseRelayMsg flag

Settings.md

@@ -64,6 +64,7 @@
     - [StripMarkdown](#stripmarkdown)
     - [UseSASL](#usesasl)
     - [UseTLS](#usetls)
+    - [UseRelayMsg](#userelaymsg)
     - [VerboseJoinPart](#verbosejoinpart)
 - [Matrix](#matrix)
     - [HTMLDisable](#htmldisable)
@@ -756,6 +757,18 @@ Example: enable it
 
 `UseTLS=true`
 
+## UseRelayMsg
+Enable to replace bot's nick with user's nick.
+`RemoteNickFormat` has to contain `/`.
+The server has to support RELAYMSG.
+Bot may need to be channel operator to use RELAYMSG.
+
+Setting: OPTIONAL \
+Format: boolean \
+Example: enable it
+
+`UseRelayMsg=true`
+
 ## VerboseJoinPart
 Enable to show verbose users joins/parts (ident@host) from other bridges
 Currently works for messages from the following bridges: irc
@@ -771,8 +784,8 @@ Example: enable it
 Basic config on https://github.com/42wim/matterbridge/wiki/Section-Matrix-(basic)
 
 ## HTMLDisable
-#Whether to disable sending of HTML content to matrix
-#See https://github.com/42wim/matterbridge/issues/1022
+Whether to disable sending of HTML content to matrix
+See https://github.com/42wim/matterbridge/issues/1022
 
 Setting: OPTIONAL, RELOADABLE \
 Format: boolean \