[documentation] "Updating your modules" moved to top-level

[Angela Byron]

Just to advise folks, I moved the "Updating your modules" section of  
the Developer's handbook (http://drupal.org/update/modules) to the  
top-level, rather than as a subsection under "Module developer's  
guide" because:

a) Now it will show up under http://drupal.org/handbooks
b) It's a commonly used reference, and you no longer have to dig two+  
levels deep in order to find it
c) The question on where to find this information was asked in  
#drupal approximately 4 gazillion times in the past week (ok, maybe  
like 10 ;))

Now hopefully we won't get 4 gazillion people asking where it went. ;)

Thanks,
-Angie