minor guide fixes for consistency (#16273)

docs/api/file-io.md

@@ -62,6 +62,14 @@ Bun.stdout;
 Bun.stderr;
 ```
 
+### Deleting files (`file.delete()`)
+
+You can delete a file by calling the `.delete()` function.
+
+```ts
+await Bun.file("logs.json").delete()
+```
+
 ## Writing files (`Bun.write()`)
 
 `Bun.write(destination, data): Promise<number>`