Fix typos in frontend docs

[gin]

What changed? Why?

1. "were" should be "where"
2. Markdown code block format ":::" should be "```"
3. Code example's "use client": should be "use client";
4. Consistent styling to RainbowKit and wagmi. Updated style to 'use client';
5. Optimism's network information URL is broken. Updated link to https://docs.optimism.io/chain/networks

Notes to reviewers
n/a

How has it been tested?
Visually.

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Name	Status	Preview	Comments	Updated (UTC)
web-base-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 8, 2024 10:27pm

[cb-heimdall]

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