Creates a directory, provided the underlying file system supports directories. SPIFFS does not, but FAT (which you may have on an attached SD card) does.
#### Syntax
`file.mkdir(path [, mode])
```
#### Parameters
- `path` the full path name of the directory to create. E.g. "/SD0/MYDIR".
- `mode` optional, only used for file systems which use mode permissions. Defaults to 0777 (octal).
#### Returns
`nil`
Throws an error if the directory could not be created. Error code 134 (at the
time of writing) indicates that the filesystem at the given path does not
support directories.
## file.rmdir()
Removes an empty directory, provided the underlying file system supports directories. SPIFFS does not, but FAT (which you may have on an attached SD card) does.
#### Syntax
`file.rmdir(path)`
#### Parameters
- `path` the path to the directory to remove. The directory must be empty.
#### Returns
`nil`
Throws an error if the directory could not be removed.