Add a comma

[pithonsmear]

It was missing :)

Not much of a contribution (sorry), but I think it should be there.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @brson (or someone else) soon.

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[3442853561]

I think this is not just an issue within the English page
Localized pages are growing. So that they are difficult to maintain.
Here's a solution #708

[alexcrichton]

Fixed in #708, but thanks for the PR!