Show more 'cd' examples?

Here are more examples of using the cd command:

Change to a Subdirectory:
If you are in /home/user and want to go to documents:
```
cd documents
```
Change to a Nested Subdirectory:
If you want to go directly to projects inside documents:
```
cd documents/projects
```
Change to a Directory with Spaces:
If the directory name has spaces, use quotes:
```
cd "My Documents"
```
or escape the space with a backslash:
```
cd My\ Documents
```
Change to a Directory Using an Absolute Path:
To change to a directory using its full path:
```
cd /home/user/documents/projects
```
Change to the Root Directory:
To go to the root of the file system:
```
cd /
```
Change to a Directory with a Shortcut:
If you have a directory named downloads in your home directory:
```
cd ~/downloads
```
Change to a Directory Using Environment Variables:
If you have an environment variable set for a directory:
```
cd $MY_DIR
```
Change to the Last Directory Visited:
To switch back to the last directory you were in:
```
cd -
```

These examples illustrate various ways to use the cd command for navigating directories in the terminal.