chore: move intro sidebar

[vinckr]

• moves concepts above guides since those are the intro documents and should be read before jumping into guides. We could alternatively make quickstarts/concepts collapsed.

Related Issue or Design Document

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Further comments

[aeneasr]

I think that guides / tutorials should be at the front and concepts later, even if they are explaining some concepts.

I would rather move some important concepts into the tutorials or guide section

[vinckr]

Maybe we move the intro documents there?
They would be important to read IMO before jumping into quickstarts.