handbook update for master branch

[Jack]

I'd like to start updating the manual/handbook for the eventual 6.2.  
I'd like to start now, with the hope of having it all or at least mostly 
done by the time we do eventually release 6.2, unlike the still 
incomplete migration from KMM4 to KMM5.

I'd also like to find a way that the process can be collaborative, but I 
don't want to clutter master branch with gobs of small commits, and I 
don't want to make extra work for translators when there is likely to be 
repeated edits to the same sections.  Would it be reasonable to create a 
Handbook-6.2 branch for this?  I can imagine there being MRs against 
this branch. This could be merged back into master when at least one or 
two chapters are complete.

Thoughts and suggestions?

Thanks.

Jack