Update usage.md

[kstefanini]

Hey!
I just ran into difficulties to make things work so I propose to move information to a more readable place

[garak]

There's already an "important" block below.
Instead of adding a redundant note, we should enhance that with the proper markdown, e.g. [!IMPORTANT] instead of **Important:**.
By the way, all the blocks should be enhanced in the same way

[kstefanini]

Thanks for your quick reply, I've updated my proposal

[garak]

At this point, why not update all the other pages as well?

[garak]

If you rebase, the CS failures should go.
After that, if you could please apply the suggested changes, I'll be glad to merge this