use assert_array_equals here
also test that this equals to a constructed instance using MultiIndex.from_tuples (but construct if by writing out the tuples)
eg make it so it doesn't depend on iter tools or other routines)
that was if some ordering changes u are covered

- add a release notes entry in improvements section 
- an example in v0.13.1
- same example in the multi-index construction section in main docs (eg where Multiindex.from_tuples is introduced)