Add "Liquidity" and "Slot 0" to ABI

[maxwolff]

Need to query liquidity and slot 0 to create Pool object, but they are not in the ethers ABI.

Ethers doesnt like \n so just did one line. could also concatination syntax or w/e

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[adjkant]

Hi! We're in the process of overhauling our examples for clarity and other improvements. Closing this as a result but we will reference this during that process!