README: added missing register() documentation

README

@@ -38,7 +38,7 @@ Then add the following to the top of your rc.lua:
   require("vicious")
 
 Once you create a widget (a textbox, graph or a progressbar) call
-vicious.register() to register it with vicious:
+vicious.register() to register it with Vicious:
 
   vicious.register(widget, wtype, format, interval, warg)
 
@@ -270,7 +270,7 @@ vicious.widgets.date
   - takes optional time offset, in seconds, as an argument for example
     to calculate time zone differences, otherwise current time is
     formatted
-  - returns the output of os.date(), formatted by provided sequences
+  - returns the output of os.date, formatted by provided sequences
 
 
 Custom widget types
@@ -292,6 +292,12 @@ branch. If you are also a BSD user you can find his work here:
 
   - http://git.sigil.org/vicious-fbsd/
 
+Some users would like to avoid writing new modules. For them Vicious
+kept the old Wicked functionality, possibility to register their own
+functions as widget types. By providing them as the second argument to
+vicious.register. Your function can accept "format" and "warg"
+arguments, just like workers.
+
 
 Power and Caching
 -----------------