Rollup merge of #76088 - hbina:add_example, r=LukasKalbertodt

Rollup merge of #76088 - hbina:add_example, r=LukasKalbertodt

Add more examples to lexicographic cmp on Iterators.

Given two arrays of T1 and T2, the most important rule of lexicographical comparison is that two arrays
of equal length will be compared until the first difference occured.

The examples provided only focuses on the second rule that says that the
shorter array will be filled with some T2 that is less than every T1.
Which is only possible because of the first rule.