Updated rust project compilation instructions in README

[Luxuride]

No description provided.

[MGlolenstine]

Thanks for the contribution!
(And I apologise for seeing it this late 😬 )

While I understand the need for code blocks in the readme, I'm wondering if there isn't too much repetition, as we repeat build and package twice.
Is there a better way of listing those options inside the code blocks without including them in their description?

Thanks for catching the remnants of the old behaviour and fixing it.