ref-manual: add migration section for 3.2

This covers most of the changes that would require action on the part of
the user that I was able to see by scouring the commits. Some of the text
was borrowed from commit messages and edited.

(From yocto-docs rev: 35e9349ba6417765274d7d1ce542e7e6f19dbe26)

Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions