broken reference to from_utf8_mut in the String documentation

[thejh]

https://doc.rust-lang.org/std/string/struct.String.html says:

To convert the mutable byte slice back into a mutable string slice, use the str::from_utf8_mut function.

with a link to https://doc.rust-lang.org/std/string/str/fn.from_utf8_mut.html . The link is dead and leads to a broken error page with a search button that leads back to the same page with more garbage in the search field. After clicking the "search" field a couple times, the pre-filled text I see is:

index html?search=index%20html%3Fsearch%3Dindex%2520html%253Fsearch%253Dindex%252520html%25253Fsearch%25253Dindex%25252520html%2525253Fsearch%2525253Dfn%2525252520from_utf8_mut

[ollie27]

Good find, but this is duplicate of #32129.

[steveklabnik]

closing as duplicate, thank you!