Update README.md (#12182)

* Update README.md

Specify the full dir

* Update examples/dreambooth/README.md
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

---------
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>

examples/dreambooth/README.md

@@ -19,8 +19,9 @@ cd diffusers
 pip install -e .
 ```
 
-Then cd in the example folder and run
+Install the requirements in the `examples/dreambooth` folder as shown below.
 ```bash
+cd examples/dreambooth
 pip install -r requirements.txt
 ```