doc: releases: resolved issues for v3.2.0

Adding the list of closed bugs since v3.1.0:

./scripts/release/list_issues.py -o zephyrproject-rtos -r zephyr -s
  2022-06-05 -f issues.txt

And some manual fixup to make doxygen happy.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>