API to use files as a lock. Supports non-std crates by disabling feature
`std`.
Currently, only one type is provided: [`LockFile`]. It does not destroy the
file after closed and behaviour on locking different file handles owned by
the same process is different between Unix and Windows. # Example:
```rust
use fslock::LockFile;
fn main() -> Result<(), fslock::Error> {
}
```