Strategized with @balazsorban44 to open one larger PR, with changes to individual examples as separate commits.
For each example, I researched how multiple realworld codebases use the featured technology with TypeScript, to thoughtfully convert them by hand - nothing automated whatsoever.
## Documentation / Examples
- [X] Make sure the linting passes by running `pnpm lint`
- [X] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)
x-ref: https://github.com/vercel/styled-jsx/issues/763
* Add 2nd arg `options` to `docCtx.defaultGetInitialProps` to make customization easier
* Upgrade styled-jsx to fit typing
* Update styled-jsx csp example
