Add weechat highlighting doku

documentation/weechat.markdown

@@ -8,7 +8,7 @@ Installation
 ------------
 
 ```
-aptitude install weechat weechat-plugins
+apt install weechat weechat-plugins
 ```
 
 
@@ -63,8 +63,8 @@ that can be loaded as follows
 If you encounter any errors, you may need to install some dependencies first:
 
 ```
-aptitude install weechat-scripts
-aptitude install python-notify python-notify2
+apt install weechat-scripts
+apt install python-notify python-notify2
 ```
 
 
@@ -104,3 +104,42 @@ cat /etc/letsencrypt/live/example.com/privkey.pem \
 chown johndoe:johndoe /home/johndoe/.weechat/ssl/relay.pem
 printf '%b' '*/relay sslcertkey\n' > /home/johndoe/.weechat/weechat_fifo_*
 ```
+
+## Notifications
+
+This example shows how to configure separate notification rules per channel. It will set the follwoing notification settings:
+
+- notify about messages in all channes (global server setting)
+- always notify in `#important-channel`
+- never notify in `#crowded-channel`
+
+```
+/set weechat.notify.irc.phys message
+/set weechat.notify.irc.phys.#important-channel all
+/set weechat.notify.irc.phys.#crowded-channel none
+```
+
+Possible options:
+
+Notify level | Level of messages added to hotlist
+------------ | ----------------------------------
+`none`       | (none)
+`highlight`  | highlight + private
+`message`    | highlight + private + message
+`all`        | highlight + private + message + low
+
+### Highlights
+
+To enable highlights, when a user sends a message important for all users like `*: important msg for all...` set the following parameter:
+
+```
+/set irc.look.highlight_regex ".*\*:.*"
+```
+
+### Set extra highlights on buffer
+
+You can force highlight using a regular expression with the buffer property "highlight_regex". For example to force the highlight on all messages in the current buffer:
+
+```
+/buffer set highlight_regex .*
+```