[Orgmode] Feature request - add a new heading with a lower level than current

[Charles Cave]

org-mode has the feature of entering M-RET to insert a heding with the same
level as current.

I would like a command to enter a new headline at a level BELOW the current
headline.  The command key binding could be a modificaton to M-RET maybe adding
the ctl or shift key.

The reason for this functionality is when using org-mode for brainstorming.
I want to quickly add more than one child heading to the current heading.
Adding the first child heading is slower because I have to do a M-RET
backspace backspace  asterisk (*) space the continue.  The next headline
is added with a M-RET.

Mindmapping programs call this a Rapid Fire brainstorming.   

If someone coud suggest how to modify the org-el code to do so this would be
great. I found references to overriding the self-insert-command function but 
couldn
find how M-Ret is implemented.

Thanks
Charles