Mention unit stride in the RAJA Views lesson

[kab163]

In the Intro Tutorial's RAJA Views lesson, we should mention something on unit stride and how it can improve performance when using RAJA Views

https://github.com/LLNL/raja-suite-tutorial/tree/main/Intro_Tutorial/lessons/09_raja_view

[artv3]

maybe we should use the make permuted view method? @rchen20 @johnbowen42