It's been a while since I used PHP, but many of those examples are _very_ bad, and encourage very poor practices.
I plan on having examples built-in with the documentation for everything, but actually approved by the team, rather than just as comments. They'll be much higher quality that way.
One of the things I love about Go's documentation is that all examples are runnable in the Go Playground, right there, inline. You can take an example, modify it, and see how things change. Rust would benefit greatly from that same functionality.
It also forces documentation to be up-to-date; one of the reasons I selected Go over Rust a year ago (besides more mature libraries and better documentation) was the fact that Rust seemed to be rapidly changing.
I don't disagree on PHP.net's user supplied examples being horrible at times. I thought that an example voting system would help regulate bad examples. Team approved examples could also be excellent. Does that mean users could supply examples and then moderators would approve the examples?
I wish you the best luck with the new rust documentation and have well placed high expectations for what you will likely do with it.
I plan on having examples built-in with the documentation for everything, but actually approved by the team, rather than just as comments. They'll be much higher quality that way.