docs: improve readme and contribution docs

[ThimoDEV]

After this https://discord.com/channels/1047126995424780288/1051880028268408913/1221556159962419322 message on Discord I changed the Readme and contribution docs slightly to be (in my opinion) a bit more attractive and easier to follow for potential new contributors to the project.

It also follows up with one small typo fix to avoid an error in the playground

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