Add weechat filters

documentation/weechat.markdown

@@ -161,3 +161,36 @@ Save all options:
 ```
 /save
 ```
+
+### Filter
+
+Enable smart filter for `join/part/quit` messages on a specific channel (example: `#openldap`):
+
+```
+/filter add irc_smart_openldap irc.freenode.#openldap irc_smart_filter *
+```
+
+You can hide only join or part/quit with following options:
+
+```
+/set irc.look.smart_filter_join on
+/set irc.look.smart_filter_quit on
+```
+
+You can setup delay (in minutes), only filter if a nick did not speak during last 5 minutes:
+
+```
+/set irc.look.smart_filter_delay 5
+```
+
+You can use regex to filter any message. For example to filter all server messages for connecting/exiting clients:
+
+```
+/filter add irc_filter_connect_disconnect * * \*\*\* Client (connect|exit)ing: 
+```
+
+Get help:
+
+```
+/help filter
+```