Standardize doc style for 'update_counters()' [ci skip]

[sharang-d]

Before:

After:

General style:

[sharang-d]

There are a lot of other places where different formatting is used. I can't make out if it is on purpose or a mistake:

[rafaelfranca]

We need to be consistent. Check which one is more used and change all others to follow it.

[sharang-d]

Yes, I figured the consistency part but I am a little confused because there are some docs wherein 3= and/or 2= and/or 4= are used(in the same method doc i.e.). I don't know if they are really used to make different heading levels or they are just mistakes. Did you mean to say we should always use 4=?