I'm not sure what you mean. Is it that you want to be able to:

Start recording
Type a comment, f.e. "I'm going to click foo"
Click foo

and so on? or something else?

This is aimed at people recording complex testcases, to help break up the resulting script.

For example, Fiona is recording a script that sends an email to yourself and checks you get it:
(i) She start recording
(ii) She clicks on "Add a Comment" and writes "Sending an email"
(iii) She then uses the UI of the app under test to compose the email and sends it
(iv) She clicks on "Add a Comment" and writes "Now check to see if we got the email"
(v) She then uses the UI of the app under test to try to find the email, and gets it into a certain state

The idea is to let you break up the script into more manageable chunks, and annotate what you're doing.

It's been possible for a while now to edit the script text while the recorder was stopped. I've just made it so that the script text is editable even while recording. So we don't need a special "Add a comment button" - you can just type:

# Sending an email

directly into the script text.