Performance: optimize hero images

[pettinarip]

Description

Implements the sizes prop where it is missing to get a more optimized image especially in smaller resolutions.

[netlify]

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Lighthouse	7 paths audited Performance: 47 (🟢 up 9 from production) Accessibility: 92 (no change from production) Best Practices: 89 (🔴 down 3 from production) SEO: 93 (no change from production) PWA: - View the detailed breakdown and full score reports

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[github-actions]

Page	Performance	Accessibility	Best practices	SEO	PWA
/en/	🟠 50	🟢 94	🟢 93	🟢 93	🔴 38
/en/wallets/find-wallet/	🟠 51	🟠 88	🟢 96	🟢 93	🔴 38
/en/staking/	🟠 51	🟢 91	🟢 93	🟢 93	🔴 38
/en/whitepaper/	🟠 65	🟢 95	🟢 96	🟢 93	🔴 38
/en/nft/	🔴 45	🟢 95	🟢 96	🟢 93	🔴 38
/en/developers/docs/intro-to-ethereum/	🟠 61	🟢 94	🟢 96	🟢 93	🔴 38
/en/developers/tutorials/creating-a-wagmi-ui-for-your-contract/	🟠 60	🟠 88	🟢 96	🟢 93	🔴 38

Lighthouse scores are calculated based on the latest audit results

[nhsz]

LGTM