Add information how to fix common build error on Windows in symlink-install-tree

Add information how to fix common build error on Windows in symlink-install-tree

By default, Windows doesn't allow to create soft links for user account
and only administrator is allowed to do this. To fix this problem you have
to raise your permissions or enable Developer Mode, which available since
Windows 10. Additional explanation when build fails will allow developer
to fix the problem on his computer faster.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1386
Signed-off-by: Mateusz Krawczuk <mat.krawczuk@gmail.com>
Message-Id: <20230504211101.1386-1-mat.krawczuk@gmail.com>
[thuth: Drop the hunk with the white space changes]
Signed-off-by: Thomas Huth <thuth@redhat.com>