godoc/style.css: enable horizontal scroll on textarea

[ghost]

previously Example codes would wrap around for long lines on smaller screen.

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[ghost]

@googlebot I signed it!

[gopherbot]

This PR (HEAD: 8446d05) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/website/+/324672 to see it.

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[gopherbot]

Message from Go Bot:

Patch Set 1:

Congratulations on opening your first change. Thank you for your contribution!

Next steps:
A maintainer will review your change and provide feedback. See
https://golang.org/doc/contribute.html#review for more info and tips to get your
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Please don’t reply on this GitHub thread. Visit golang.org/cl/324672.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from David Chase:

Patch Set 1:

(1 comment)

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Please don’t reply on this GitHub thread. Visit golang.org/cl/324672.
After addressing review feedback, remember to publish your drafts!