Document that `Display` entails `ToString`

[steffahn]

I just answered a question on URLO about when to implement or not to implement Display, and I noticed that the docs on the Display trait are lacking.

In particular, I believe they should definitely point out that implementing Display will give a type a .to_string() method via the ToString trait. This is important to keep in mind when you’re designing an API; it’s also the reason why in the standard library Path doesn’t implement Display directly (but offers a .display() method): because converting Path to String is lossy or fallible, and an (implicitly) lossy to_string method would not fit the API.

@rustbot label A-docs, C-enhancement, T-libs-api

[JKAnderson409]

@rustbot claim

[sigaloid]

@rustbot claim

Edit: Not sure if I stole this from you @JKAnderson409 , on my end it looks like you were unassigned most recently.