Update unconditional_image_generation.mdx (#2686)

Fix typos

docs/source/en/using-diffusers/unconditional_image_generation.mdx

@@ -14,7 +14,7 @@ specific language governing permissions and limitations under the License.
 
 # Unconditional Image Generation
 
-The [`DiffusionPipeline`] is the easiest way to use a pre-trained diffusion system for inference
+The [`DiffusionPipeline`] is the easiest way to use a pre-trained diffusion system for inference.
 
 Start by creating an instance of [`DiffusionPipeline`] and specify which pipeline checkpoint you would like to download.
 You can use the [`DiffusionPipeline`] for any [Diffusers' checkpoint](https://huggingface.co/models?library=diffusers&sort=downloads).