### What it does
Checks usage of `std::fs::create_dir` and suggest using `std::fs::create_dir_all` instead.

### Why is this bad?
Sometimes `std::fs::create_dir` is mistakenly chosen over `std::fs::create_dir_all`.

### Example
```
std::fs::create_dir("foo");
```

Use instead:
```
std::fs::create_dir_all("foo");
```