docs(next/script): Improve formatting of docs (#26149)
docs(next/script): Improve formatting of docs (#26149)

Noticed a few things off in the Script docs—for example, the "before" variant should show using a non-React Component `<script>` tag, & the capitalization was inconsistent in a few places.

## Documentation / Examples

- [x] Make sure the linting passes

zeit/next.js,azukaru/next.js,azukaru/next.js,zeit/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js,JeromeFitz/next.js,flybayer/next.js,zeit/next.js,flybayer/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,flybayer/next.js