feat: Add trailing `;` when typing `=` in assignment
This does have a false positive to keep in mind, it will add a trailing `;` in the following snippet too, which is probably not desired:
```rust
fn is_zero(i: i32) -> bool {
i $0 0
}
```
However, that function is unlikely to be written from the "inside out" like that, so it might be acceptable. Typically `=` is only inserted last when the author realizes that an existing expression should be assigned to some variable.
63573d47aa
