Moving or renaming directories (mvdir command)

Use the mvdir command to move or rename a directory.

The following are examples of how to use the mvdir command:

To move a directory, type the following:
```
mvdir book manual
```
This moves the book directory under the directory named manual, if the manual directory exists. Otherwise, the book directory is renamed to manual.
To move and rename a directory, type the following:
```
mvdir book3 proj4/manual
```
If a directory named manual already exists, this moves book3 and its contents to proj4/manual. In other words, book3 becomes a subdirectory of proj4/manual. If manual does not exist, this renames the book3 directory to proj4/manual.