To update help:

edit Help_En.dat 

Be sure that the data  for the command is in the treebox adds section.

the command data sections needs:

&
command

Name:
command -- what is does:

Synopsis:
the command 

Description:
what is does

Example:
example use

Related: related commands
&

Note: the & before and after the command information. 

run GenerateIndex.yab from the data directory to make a new Help_En_Index.dat